You were dead in your transgressions and sins in which you once lived following the age of this world, following the ruler of the power of the air, the spirit that is now at work in the disobedient. All of us once lived among them in the desires of our flesh, following the wishes of the flesh and the impulses, and we were by nature children of wrath, like the rest. But God, who is rich in mercy, because of the great love he had for us, even when we were dead in our transgressions, brought us to life with Christ (by grace you have been saved), raised us up with him, and seated us with him in the heavens in Christ Jesus, that in the ages to come he might show the immeasurable riches of his grace in his kindness to us in Christ Jesus. For by grace you have been saved, through faith, and this is not from you; it is the gift of God; it is not from works, so no one may boast. (Eph 2:1 – 9)

Grace is a participation in the life of God. It introduces us into the intimacy of Trinitarian life. […] He receives the life of the Spirit who breathes charity into him and who forms the Church. This vocation to eternal life is supernatural. It depends entirely on God’s gratuitous initiative, for he alone can reveal and give himself. It surpasses the power of human intellect and will, as that of every other creature. The grace of Christ is the gratuitous gift that God makes to us of his own life, infused by the Holy Spirit into our soul to heal it of sin and to sanctify it. It is the sanctifying or deifying grace received in Baptism. It is in us the source of the work of sanctification. (Catechism of the Catholic Church, no. 1997 – 1999)

Grace is an inward and supernatural gift

What is grace?
Grace is an inward and supernatural gift given to us without any merit of our own, but through the merits of Jesus Christ in order to gain eternal life. (Catechism of Saint Pius X, The Sacraments, no. 10)

Let us recall from the catechism: grace is God’s supernatural gift as the result of which we become children of God and heirs to heaven. […] In this gift to man God did not just ‘give him’ the visible world – this is clear from the beginning – but giving man the visible world, God wants to give him Himself too, just as man is capable of giving himself, just as he ‘gives himself’ to the other man: from person to person; that is, to give Himself to him, admitting him to participation in his mysteries, and even to participation in his life. […] Man is called to familiarity with God, to intimacy and friendship with him. God wants to be close to him. He wants to make him a participant in his plans. He wants to make him a participant in his life. He wants to make him happy with his own happiness (with his own Being). (John Paul II. General audience, no. 2 – 3, December 13, 1978)

Through the gift of grace, which comes from the Holy Spirit, man enters a ‘new life,’ is brought into the supernatural reality of the divine life itself and becomes a ‘dwelling-place of the Holy Spirit,’ a living temple of God. For through the Holy Spirit, the Father and the Son come to him and take up their abode with him. In the communion of grace with the Trinity, man’s ‘living area’ is broadened and raised up to the supernatural level of divine life. Man lives in God and by God: he lives ‘according to the Spirit,’ and ‘sets his mind on the things of the Spirit.’ (John Paul II. Encyclical Dominum et vivificantem, no. 58, May 18, 1986)

See in the same Psalm those to whom he says, ‘I have said, You are gods, and children of the Highest all; but you shall die like men, and fall like one of the princes.’ It is evident then, that He has called men gods, that are deified of His Grace, not born of His Substance. For He does justify, who is just through His own self, and not of another; and He does deify who is God through Himself, not by the partaking of another. But He that justifies does Himself deify, in that by justifying He does make sons of God. ‘For He has given them power to become the sons of God’ (Jn 1:12). If we have been made sons of God, we have also been made gods: but this is the effect of Grace adopting, not of nature generating. For the only Son of God, God, and one God with the Father, Our Lord and Saviour Jesus Christ, was in the beginning the Word, and the Word with God, the Word God. The rest that are made gods, are made by His own Grace, are not born of His Substance, that they should be the same as He, but that by favour they should come to Him, and be fellow-heirs with Christ. For so great is the love in Him the Heir, that He has willed to have fellow-heirs. What covetous man would will this, to have fellow-heirs? But even one that is found so to will, will share with them the inheritance, the sharer having less himself, than if he had possessed alone: but the inheritance wherein we are fellow-heirs of Christ, is not lessened by multitude of possessors, nor is it made narrower by the number of fellow-heirs: but is as great for many as it is for few, as great for individuals as for all. (Saint Augustine of Hippo. Exposition on Psalm 50, no. 2)

This is the reason why there has been vouchsafed to us, through the Mediator, this grace, that we who are polluted by sinful flesh should be cleansed by the likeness of sinful flesh. By this grace of God, wherein He has shown His great compassion toward us, we are both governed by faith in this life, and, after this life, are led onwards to the fullest perfection by the vision of immutable truth. (Saint Augustine of Hippo. City of God, Book X, Ch. 22)

In order to live righteously a man needs a twofold help of God – first, a habitual gift whereby corrupted human nature is healed, and after being healed is lifted up so as to work deeds meritoriously of everlasting life, which exceed the capability of nature. Secondly, man needs the help of grace in order to be moved by God to act. Now with regard to the first kind of help, man does not need a further help of grace, e.g. a further infused habit. Yet he needs the help of grace in another way, i.e. in order to be moved by God to act righteously, and this for two reasons: first, for the general reason that no created thing can put forth any act, unless by virtue of the Divine motion. Secondly, for this special reason – the condition of the state of human nature. For although healed by grace as to the mind, yet it remains corrupted and poisoned in the flesh, whereby it serves ‘the law of sin’ (Rom 7:25). (Saint Thomas Aquinas. Summa Theologica I-II, q. 109, a. 9)

How is grace distinguished?
Grace is divided into sanctifying grace, which is also called habitual grace, and actual grace.
What is sanctifying grace?
Sanctifying grace is a supernatural gift inherent in our soul, and rendering us just, adopted children of God and heirs to Paradise. […] What is actual grace?
Actual grace is a supernatural gift which enlightens the mind, moves and strengthens the will in order to enable us to do good and avoid evil. (Catechism of Saint Pius X, The Sacraments, no. 11 – 12, 16)

TSanctifying grace is an habitual gift, a stable and supernatural disposition that perfects the soul itself to enable it to live with God, to act by his love. Habitual grace, the permanent disposition to live and act in keeping with God’s call, is distinguished from actual graces which refer to God’s interventions, whether at the beginning of conversion or in the course of the work of sanctification. (Catechism of the Catholic Church, no. 2000)

The whole Christian life is lived in faith and charity, and in the practice of all of the virtues, according to the interior action of this renewing Spirit, from whom proceeds the grace that justifies, vivifies and sanctifies; and with grace comes all the new virtues which constitute the fabric of the supernatural life. This life develops not only by the natural faculties of man – the intellect, will, and senses – but also by the new capacities that are added on (superadditae) along with grace, as Saint Thomas Aquinas explains (STh., I-II, q. 62, a. 1, 3). These give to the intellect the ability to adhere to God-Truth in faith; to the heart the ability to love in charity, which in man is like ‘a participation in the divine Love itself, the Holy Spirit’ (II-II, q. 23, a. 3, ad 3); and also [they give] to all the powers of the soul and in some way to the body, too, a participation in the new life with acts worthy of men elevated to participating in the nature and in the life of God in grace: ‘consortes divinae naturae’, as Saint Peter says (2Pet 1:4). It is like a new interior organism, in which the law of grace is made manifest: a law written in hearts rather than on stone tablets or paper codices. Saint Paul calls this law, as we have seen, ‘the law of the Spirit that gives life in Christ Jesus’ (Rom 8, 2). (John Paul II. General audience, no. 2, April 3, 1991)

The Most Holy Trinity gives the baptized sanctifying grace, the grace of justification:
– enabling them to believe in God, to hope in him, and to love him through the theological virtues;
– giving them the power to live and act under the prompting of the Holy Spirit through the gifts of the Holy Spirit;
– allowing them to grow in goodness through the moral virtues. (Catechism of the Catholic Church, no. 1266)

The theological virtues are the foundation of Christian moral activity; they animate it and give it its special character. They inform and give life to all the moral virtues. They are infused by God into the souls of the faithful to make them capable of acting as his children and of meriting eternal life. They are the pledge of the presence and action of the Holy Spirit in the faculties of the human being. (Catechism of the Catholic Church, no. 1813)

Augustine says (De Perfect Just. XXI): ‘Whoever denies that we ought to say the prayer ‘Lead us not into temptation’ (and they deny it who maintain that the help of God’s grace is not necessary to man for salvation, but that the gift of the law is enough for the human will) ought without doubt to be removed beyond all hearing, and to be anathematized by the tongues of all.’ (Saint Thomas Aquinas. Summa Theologica I-II, q. 109, a. 8)

No instrument can achieve its ultimate perfection by the power of its own form, but only by the power of the principal agent, although by its own power it can provide a certain disposition to the ultimate perfection. Indeed, the cutting of the lumber results from the saw according to the essential character of its own form, but the form of the bench comes from the skilled mind which uses the tool. Likewise, the breaking down and consumption of food in the animal body is due to the heat of fire, but the generation of flesh, and controlled growth and similar actions, stem from the vegetative soul which uses the heat of fire as an instrument. Now, all intellects and wills are subordinated as instruments under a principal agent to God, Who is the first intellect and will. So, their operations must have no efficacy in regard to the ultimate perfection which is the attainment of final happiness, except through the divine power. Therefore, a rational nature needs divine help to obtain the ultimate end. […] Since what is given a person, without any preceding merit on his part, is said to be given to him gratis, and because the divine help that is offered to man precedes all human merit, as we showed, it follows that this help is accorded gratis to man, and as a result it quite fittingly took the name grace. Hence, the Apostle says, in Romans (Rom 11:6): ‘And if by grace, it is not now by works: otherwise grace is no more grace.’ (Saint Thomas Aquinas. Summa Contra Gentiles, Book III, ch. 147, 150)

The free gift [grace] of God is eternal life. For since he had said that just men have eternal life, which it is certain cannot be had except through grace, then the very fact that we do what is good and that our works are worthy of eternal life is the result of God’s grace: ‘He bestows grace and glory’ (Ps 84:11). Thus, therefore, if our works are considered in themselves and as coming from our free will they do not merit eternal life ex condigno, but only as coming from the grace of the Holy Spirit. (Saint Thomas Aquinas. Commentary on the Letter to the Romans, Rom 6:19 – 23)

Acts conducing to an end must be proportioned to the end. But no act exceeds the proportion of its active principle; and hence we see in natural things, that nothing can by its operation bring about an effect which exceeds its active force, but only such as is proportionate to its power. Now everlasting life is an end exceeding the proportion of human nature, as is clear from what we have said above (q. 5, a. 5). Hence man, by his natural endowments, cannot produce meritorious works proportionate to everlasting life; and for this a higher force is needed, viz. the force of grace. And thus without grace man cannot merit everlasting life […] ‘It is certain that everlasting life is meter to good works; but the works to which it is meted, belong to God’s grace.’ And it has been said (a. 4), that to fulfill the commandments of the Law, in their due way, whereby their fulfilment may be meritorious, requires grace. (Saint Thomas Aquinas. Summa Theologica I-II, q. 109, a.5)

If man has a nature, whereby he can he justified, ‘Christ died in vain,’ i.e. to no purpose. But this cannot fittingly be said. Therefore by himself he cannot be justified, i.e. he cannot return from a state of sin to a state of justice. I answer that, Man by himself can no wise rise from sin without the help of grace. For since sin is transient as to the act and abiding in its guilt, as stated above (q. 87, a. 6), to rise from sin is not the same as to cease the act of sin; but to rise from sin means that man has restored to him what he lost by sinning. Now man incurs a triple loss by sinning, as was clearly shown above (q. 85, a. 1; q. 86, a. 1; q. 87, a.1), viz. stain, corruption of natural good, and debt of punishment. He incurs a stain, inasmuch as he forfeits the lustre of grace through the deformity of sin. Natural good is corrupted, inasmuch as man’s nature is disordered by man’s will not being subject to God’s; and this order being overthrown, the consequence is that the whole nature of sinful man remains disordered. Lastly, there is the debt of punishment, inasmuch as by sinning man deserves everlasting damnation. Now it is manifest that none of these three can be restored except by God. For since the lustre of grace springs from the shedding of Divine light, this lustre cannot be brought back, except God sheds His light anew: hence a habitual gift is necessary, and this is the light of grace. Likewise, the order of nature can only be restored, i.e. man’s will can only be subject to God when God draws man’s will to Himself, as stated above (a. 6). So, too, the guilt of eternal punishment can be remitted by God alone, against Whom the offense was committed and Who is man’s Judge. And thus in order that man rise from sin there is required the help of grace, both as regards a habitual gift, and as regards the internal motion of God. (Saint Thomas Aquinas. Summa Theologica I-II, q. 109, a. 7)

By sinning a man offends God as stated above (q. 71, a. 5). Now an offense is remitted to anyone, only when the soul of the offender is at peace with the offended. Hence sin is remitted to us, when God is at peace with us, and this peace consists in the love whereby God loves us. Now God’s love, considered on the part of the Divine act, is eternal and unchangeable; whereas, as regards the effect it imprints on us, it is sometimes interrupted, inasmuch as we sometimes fall short of it and once more require it. Now the effect of the Divine love in us, which is taken away by sin, is grace, whereby a man is made worthy of eternal life, from which sin shuts him out. Hence we could not conceive the remission of guilt, without the infusion of grace. (Saint Thomas Aquinas. Summa Theologica I-II, q. 113, a. 2)

And in this way, neither in the state of perfect nature, nor in the state of corrupt nature can man fulfil the commandments of the law without grace. Hence, Augustine (De Corrupt. et Grat. II) having stated that ‘without grace men can do no good whatever,’ adds: ‘Not only do they know by its light what to do, but by its help they do lovingly what they know.’ Beyond this, in both states they need the help of God’s motion in order to fulfil the commandments, as stated above (a.2,3). (Saint Thomas Aquinas. Summa Theologica I-II, q. 109, a. 4)

From which examples we are undoubtedly reminded that there are two sorts of aids. Some are indispensable, and without their help the desired result could not be attained. Without a ship, for instance, no man could take a voyage; no man could speak without a voice; without legs no man could walk; without light nobody could see; and so on in numberless instances. Amongst them this also may be reckoned, that without God’s grace no man can live rightly. (Saint Augustine of Hippo. On the proceedings of Pelagius, Ch. 3)

This is the religion which possesses the universal way for delivering the soul; for except by this way, none can be delivered. This is a kind of royal way, which alone leads to a kingdom which does not totter like all temporal dignities, but stands firm on eternal foundations. […] For what else is the universal way of the soul’s deliverance than that by which all souls universally are delivered, and without which, therefore, no soul is delivered? […] What is this universal way of which he acknowledges his ignorance, if not a way which does not belong to one nation as its special property, but is common to all, and divinely bestowed? Porphyry, a man of no mediocre abilities, does not question that such a way exists; for he believes that Divine Providence could not have left men destitute of this universal way of delivering the soul. […] this universal way of the soul’s deliverance […] the grace of God […] This way purifies the whole man, and prepares the mortal in all his parts for immortality. […] Except by this way, which has been present among men both during the period of the promises and of the proclamation of their fulfillment, no man has been delivered, no man is delivered, no man shall be delivered. (Saint Augustine of Hippo. The City of God, Book X, Ch. 32)

Will someone say, Why, then, was this divine compassion extended even to the ungodly and ungrateful? Why, but because it was the mercy of Him who daily ‘makes His sun to rise on the evil and on the good, and sends rain on the just and on the unjust’ (Mt 5:45). For though some of these men, taking thought of this, repent of their wickedness and reform, some, as the apostle says, ‘despising the riches of His goodness and long-suffering, after their hardness and impenitent heart, treasure up unto themselves wrath against the day of wrath and revelation of the righteous judgment of God, who will render to every man according to his deeds’ (Rom 2:4). (Saint Augustine of Hippo. The City of God, Book I, ch. VIII, no. 1)

No one is good by himself unless the One who alone is good grants him a sharing in himself. And this is attested by the declaration of the same pontiff in the same document, saying: ‘In times to come are we actually to judge what is right on the basis of the opinions of those who think they are indebted to themselves for the fact that they are good, who do not take into account the One whose grace they receive every day, and who are confident that they can attain to so much without him? In addition, no one, even if renewed by the grace of baptism, is able to overcome the snares of the devil or subdue the passions of the flesh unless he receives, through the daily help of God, the gift of perseverance in remaining good. And the teaching of the same prelate confirms this in the same pages, saying: ‘For although he had redeemed man from previous sins, nevertheless, knowing that he could sin again, he retained many means for healing him again, by which he might correct him even after those (subsequent sins), providing him with daily remedies: and if we do not support ourselves by relying upon these and trusting in them to no extent shall we be able to overcome human failings. For it is necessary that, just as we are victorious with his help, so, on the other hand, we are overcome without his help. (Denzinger-Hünermann 240-241. Celestine I. Letter Apostolica verba to the Bishops of Gaul, Canons on grace, Pseudo-Celestine Chapters or Indiculus, May 431 – Parts in English – Dz 131-132)

Likewise, it has been decided that whoever says that the grace of God, by which man is justified through Jesus Christ, our Lord, has power only for the remission of sins that have already been committed and not also for help that they be not committed, let him be anathema. In like manner, whoever says that the same grace of God through Jesus Christ, our Lord, helps us not to sin only for this reason, that through it the understanding of the commands is revealed and opened to us, that we may know what we ought to strive after, what we ought to avoid, but that through this (the power) is not also given to us to love and to be able to do that which we know ought to be done, let him be anathema. For since the apostle says: ‘Knowledge puffs up, but charity edifies’ (1Cor 8:1), it is very impious for us to believe that for that which puffs up, we have the grace of Christ, and for that which edifies we have not, although each is a gift of God, both to know what we ought to do and to love in order that we may do it, so that while charity edifies, knowledge may not be able to puff us up. Moreover, just as it is written of God: ‘He teaches man knowledge’ (Ps 94:10), so also it its written: ‘Charity is from God’ (1Jn 4:7). It has likewise been decided that whoever says that the grace of justification is given to us so that we may accomplish more easily by grace what we are ordered to do by free will, as though, even if grace were not given, we could still fulfil the divine commands without it, though not as easily, let him be anathema. For when he spoke of the fruit of the commandments, the Lord did not say: ‘Without me you can accomplish with greater difficulty’, but: ‘Without me you can do nothing’ (Jn 15:5). (Denzinger-Hünermann 225-227. Fifteenth Synod of Carthage, Canons on Grace, May 1, 418 – Parts in English in Denzinger 103-105)

But although Christ died for all (2Cor 5:15), yet not all receive the benefit of His death, but those only to whom the merit of His passion is communicated. For, as indeed men would not be born unjust, if they were not born through propagation of the seed of Adam, since by that propagation they contract through him, in conception, injustice as their own, so unless they were born again in Christ, they never would be justified [can. 2 and 10], since in that new birth through the merit of His passion, the grace, whereby they are made just, is bestowed upon them. For this benefit the Apostle exhorts us always to ‘give thanks to the Father who has made us worthy to be partakers of the lot of the saints in light’ (Col 1:12), ‘and has delivered us from the power of darkness, and has translated us into the kingdom of the Son of his love, in whom we have redemption and remission of sins’ (Col 1:13 ff). (Denzinger-Hünermann 1523. Council of Trent, Session VI, Decree on justification, January 13, 1547 – Denzinger 795)

On the contrary, before sin, man bore in his soul the fruit of eternal election in Christ, the eternal Son of the Father. By means of the grace of this election man, male and female, was ‘holy and blameless’ before God. That primordial (or original) holiness and purity were expressed also in the fact that, although both were ‘naked, they were not ashamed’ (Gen 2:25) […] one must deduce that the reality of man’s creation was already imbued by the perennial election of man in Christ. Man is called to sanctity through the grace of the adoption as sons. ‘He destined us to be his sons through Jesus Christ, according to the purpose of his will, to the praise of his glorious grace which he freely bestowed on us in the Beloved’ (Eph 1:5 – 6). Man, male and female, shared from the beginning in this supernatural gift. This bounty was granted in consideration of him, who from eternity was beloved as Son, even though – according to the dimensions of time and history – it had preceded the Incarnation of this beloved Son and also the redemption which we have in him through his blood (cf. Eph 1:7). The redemption was to become the source of man’s supernatural endowment after sin and, in a certain sense, in spite of sin. This supernatural endowment, which took place before original sin, that is, the grace of justice and original innocence – an endowment which was the fruit of man’s election in Christ before the ages – was accomplished precisely in reference to him, to the beloved One, while anticipating chronologically his coming in the body. (John Paul II. General audience, no. 4-5, October 6, 1982)

For the sacraments signify grace and confer grace: they signify life and give life. The Church is the visible dispenser of the sacred signs, while the Holy Spirit acts in them as the invisible dispenser of the life which they signify. Together with the Spirit, Christ Jesus is present and acting. (John Paul II. Encyclical Dominum et vivificantem, no. 63, May 18, 1986)

The principal effects of the Sacraments are two. The first place is rightly held by that grace which we, following the usage of the holy Doctors, call sanctifying. For so the Apostle most clearly taught when he said: Christ loved the church, and delivered himself up for it; that he might sanctify it, cleansing it by the laver of water in the word of life. But how so great and so admirable an effect is produced by the Sacrament that, to use the well­known saying of Saint Augustine, water cleanses the body and reaches the heart, this, indeed, cannot be comprehended by human reason and intelligence. It may be taken for granted that no sensible thing is of its own nature able to reach the soul; but we know by the light of faith that in the Sacraments there exists the power of almighty God by which they effect that which the natural elements cannot of themselves accomplish. (Catechism of Trent, 2000)

There are seven sacraments of the new Law: namely, baptism, confirmation, Eucharist, penance, extreme unction, orders, and matrimony, which differ a great deal from the sacraments of the Old Law. For those of the Old Law did not effect grace, but only pronounced that it should be given through the passion of Christ; these sacraments of ours contain grace, and confer it upon those who receive them worthily. (Denzinger-Hünermann 1310. Eugene IV, Bull Exultate Deo, November 22, 1439 – Dz 695)

‘But,’ he [Pope Stephan] says, ‘the name of Christ conduces greatly to faith and to the sanctification of baptism, so that whoever has been baptized anywhere in the name of Christ, at once obtains the grace of Christ.’ (Denzinger-Hünermann 111. Stephan I, Letter to the Bishops of Asia Minor, 256)

But one who submits to Christ’s sacraments obtains grace from his power, so as not to be under the Law but under grace, unless they enslaved themselves to sin through their own fault. (Saint Thomas Aquinas. Commentary on the Letter to the Romans, Rom 6:11 – 18)

Against the crafty genius of certain men also, who ‘by pleasing speeches and good words seduce the hearts of the innocent’ (Rom 16:18), it must be maintained that the grace of justification, although received, is lost not only by infidelity [can. 27], whereby even faith itself is lost, but also by any other mortal sin, although faith be not lost [can. 28]. (Denzinger-Hünermann 1544. Council of Trent, Session VI, ch. XV, Decree on justification, January 13, 1547)

Since it belongs to the supernatural order, grace escapes our experience and cannot be known except by faith. We cannot therefore rely on our feelings or our works to conclude that we are justified and saved (cf. Council of Trent). However, according to the Lord’s words ‘Thus you will know them by their fruits’ (Mt 7:20), reflection on God’s blessings in our life and in the lives of the saints offers us a guarantee that grace is at work in us and spurs us on to an ever greater faith and an attitude of trustful poverty. A pleasing illustration of this attitude is found in the reply of Saint Joan of Arc to a question posed as a trap by her ecclesiastical judges: ‘Asked if she knew that she was in God’s grace, she replied: ‘If I am not, may it please God to put me in it; if I am, may it please God to keep me there’ (Acts of the trial of Saint Joan of Arc). (Catechism of the Catholic Church, no. 2005)

Lest on this subject any doubt should exist in the minds of the faithful, God, in the abundance of His mercy, was pleased, from the moment when the Sacraments began to be administered, to manifest by the evidence of miracles the effects which they operate interiorly in the soul. (This He did) in order that we may most firmly believe that the same effects, although far removed from the senses, are always inwardly produced. To say nothing of the fact that at the Baptism of the Redeemer in the Jordan the heavens were opened and the Holy Ghost appeared in the form of a dove, to teach us that when we are washed in the sacred font His grace is infused into our souls – to omit this. (Council of Trent, 2000)

There are three ways of knowing a thing: first, by revelation, and thus anyone may know that he has grace, for God by a special privilege reveals this at times to some, in order that the joy of safety may begin in them even in this life, and that they may carry on toilsome works with greater trust and greater energy, and may bear the evils of this present life, as when it was said to Paul (2 Cor. 12:9): ‘My grace is sufficient for thee.’ Secondly, a man may, of himself, know something, and with certainty; and in this way no one can know that he has grace. For certitude about a thing can only be had when we may judge of it by its proper principle. Thus it is by undemonstrable universal principles that certitude is obtained concerning demonstrative conclusions. Now no one can know he has the knowledge of a conclusion if he does not know its principle. But the principle of grace and its object is God, Who by reason of His very excellence is unknown to us, according to Job 36:26: ‘Behold God is great, exceeding our knowledge.’ And hence His presence in us and His absence cannot be known with certainty, according to Job 9:11: ‘If He come to me, I shall not see Him; if He depart I shall not understand.’ And hence man cannot judge with certainty that he has grace, according to 1Cor 4:3 – 4: ‘But neither do I judge my own self . . . but He that judgeth me is the Lord.’ Thirdly, things are known conjecturally by signs; and thus anyone may know he has grace, when he is conscious of delighting in God, and of despising worldly things, and inasmuch as a man is not conscious of any mortal sin. (Saint Thomas Aquinas. Summa Theologica I-II, q. 112, a. 5)

‘Save Your people, and bless Your inheritance; rule them, and lift them up for ever.’ They would not, of course, stay, if they are ruled only by their own will without God, even as sheep which have no shepherd: which, God forbid for us. For, unquestionably to be led is something more compulsory than to be ruled. He who is ruled at the same time does something himself – indeed, when ruled by God, it is with the express view that he should also act rightly; whereas the man who is led can hardly be understood to do any thing himself at all. And yet the Saviour’s helpful grace is so much better than our own wills and desires, that the Apostle does not hesitate to say: ‘As many as are led by the Spirit of God, they are the sons of God’ (Rom 8:14). And our free will can do nothing better for us than to submit itself to be led by Him who can do nothing amiss; and after doing this, not to doubt that it was helped to do it by Him of whom it is said in the psalm, ‘He is my God, His mercy shall go before me.’ (Saint Augustine of Hippo. On the proceedings of Pelagius, Ch. 5, no. III)

You will ask me how you can tell if you really have these two very, very great virtues. You are right to ask, for we can never be quite definite and certain about it; if we were sure that we possessed love, we should be sure that we were in a state of grace. But you know, sisters, there are some indications which are in no way secret but so evident that even a blind man, as people say, could see them. You may not wish to heed them, but they cry so loud for notice that they make quite an uproar, for there are not many who possess them to the point of perfection and thus they are the more readily noticed. (Saint Teresa of Avila. Way of perfection, Ch. 40, no.2)

Because of the abundance of the revelations. Therefore, that I might not become too elated, a thorn in the flesh was given to me, an angel of Satan, to beat me, to keep me from being too elated. Three times I begged the Lord about this, that it might leave me, but he said to me, ‘My grace is sufficient for you, for power is made perfect in weakness.’ I will rather boast most gladly of my weaknesses, in order that the power of Christ may dwell with me. (2Cor 12:7 – 9)

But by the grace of God I am what I am, and his grace to me has not been ineffective. Indeed, I have toiled harder than all of them; not I, however, but the grace of God (that is) with me. (1Cor 15:10)

Paul experienced in an extraordinary way the power of God’s grace […] All of his preaching and even more his entire missionary existence was sustained by an inner urge that can be traced back to the fundamental experience of ‘grace’. ‘By the grace of God I am what I am’, he writes to the Corinthians, ‘…I worked harder than any of them [the Apostles], though it was not I, but the grace of God which is with me’ (1Cor 15:10). It is a question of an awareness that surfaces in all his writings and that served as an inner ‘lever’ with which God could propel him onwards, toward ever further boundaries, not only geographical but also spiritual. (Benedict XVI. Homily on Ash Wednesday, February 25, 2009)

In the liturgy this Sunday the Apostle Paul speaks to us and his words deserve a reflection on our part. ‘I will rather boast most gladly of my weaknesses, in order that the power of Christ may dwell with me…for when I am weak, then I am strong’ (2Cor 12:9 – 10). In this way he writes of himself, a man who personally experienced, and in a particular way, the power of the grace of God. Praying in the midst of the difficulties of life, he heard the Lord’s reply: ‘My grace is sufficient for you, for power is made perfect in weakness’ (2Cor 12:9). Prayer is the first and fundamental condition for collaboration with the grace of God. It is necessary to pray to obtain the grace of God – and it is necessary to pray to be able to cooperate with the grace of God. This is the true rhythm of the interior life of the Christian. The Lord speaks to each one of us as he spoke to the Apostle: ‘My grace is sufficient for you, for power is made perfect in weakness.’ When we pray the Angelus, we meditate on the supreme moment of collaboration with the grace of God in the history of man. Mary, in saying: ‘Behold, I am the handmaid of the Lord. May it be done to me according to your word’ (Lk 1:38) and accepting the maternity of the Incarnate Word, unites in a very particular way her human weakness with the power of grace. Therefore, when She expresses her human fears, she hears the words: ‘The Holy Spirit will come upon you, and the power of the Most High will overshadow you’ (Lk 1:35). (John Paul II. Angelus, no. 2 – 3, July 4, 1982)

There is no reason for surprise that the tax collector abandoned earthly wealth as soon as the Lord commanded him. Nor should one be amazed that neglecting his wealth, he joined a band of men whose leader had, on Matthew’s assessment, no riches at all. Our Lord summoned Matthew by speaking to him in words. By an invisible, interior impulse flooding his mind with the light of grace, he instructed him to walk in his footsteps. In this way Matthew could understand that Christ, who was summoning him away from earthly possessions, had incorruptible treasures of heaven in his gift. (Saint Bede the Venerable. Homily 21 (CCL122, 149-151) – Second reading for the feast of St. Matthew, September 21)

Too late did I love You, O Fairness, so ancient, and yet so new! Too late did I love You! For behold, You were within, and I without, and there did I seek You; I, unlovely, rushed heedlessly among the things of beauty You made. You were with me, but I was not with You. Those things kept me far from You, which, unless they were in You, were not. You called, and cried aloud, and forced open my deafness. You gleamed and shine, and chase away my blindness. You exhaled odours, and I drew in my breath and do pant after You. I tasted, and do hunger and thirst. You touched me, and I burned for Your peace. (Saint Augustine of Hippo. The Confessions, Book 10, Ch. 27, no. 38)

And being thence warned to return to myself, I entered into my inward self, Thou leading me on; and I was able to do it, for You had become my helper. And I entered, and with the eye of my soul (such as it was) saw above the same eye of my soul, above my mind, the Unchangeable Light. Not this common light, which all flesh may look upon, nor, as it were, a greater one of the same kind, as though the brightness of this should be much more resplendent, and with its greatness fill up all things. Not like this was that light, but different, yea, very different from all these. Nor was it above my mind as oil is above water, nor as heaven above earth; but above it was, because it made me, and I below it, because I was made by it. He who knows the Truth knows that Light; and he that knows it knows eternity. Love knows it. (Saint Augustine of Hippo. The Confessions, Book VII, Ch. X, no. 16)

It happened once that, when I was publicly commending the grace of God towards me in that in any good work I both recognized that I had been prevented and felt that I was being furthered and hoped for full attainment, by its means. (Saint Bernard of Clairvaux. Concerning Grace and free will, Ch. 1)

On the Tuesday following Ascension Thursday, having remained a while in prayer after Communion, I was grieved because I was so distracted I couldn’t concentrate. So I complained to the Lord about our miserable nature. My soul began to enkindle, and it seemed to me I knew clearly in an intellectual vision that the entire Blessed Trinity was present. In this state my soul understood by a certain kind of representation (like an illustration of the truth), in such a way that my dullness could perceive, how God is three and one. And so it seemed that all three Persons were represented distinctly in my soul and that they spoke to me, telling me that from this day I would see an improvement in myself in respect to three things and that each one of these Persons would grant me a favor: one, the favor of charity; another, the favor of being able to suffer gladly; and the third, the favor of experiencing this charity with an enkindling in the soul. I understood those words the Lord spoke, that the three divine Persons would be with the soul in grace; for I saw them within myself in the way described. (Saint Teresa of Avila. Spiritual Testimonies, ch. 13, no.1 – Avila, St. Joseph, May 29, 1571)

With regard to the fear about whether or not I was in the state of grace, He told me: ‘Daughter, light is very different from darkness. I am faithful. Nobody will be lost unknowingly. They who find security in spiritual favors will be deceived. True security is the testimony of a good conscience. But people should not think that through their own efforts they can be in light or that they can do anything to prevent the night, because these states depend upon my grace. The best help for holding on to the light is to understand that you can do nothing and that it comes from me. For even though you may be in light, at the moment I withdraw, the night will come. This is true humility: to know what you can do and what I can do. (Saint Teresa of Avila. Spiritual Testimonies, ch. 24 – Avila, Convent of the Incarnation, 1572)

We can say, without any boasting, that we have received very special graces and lights; we stand in the truth and see things in their proper light. (Saint Therese of Lisieux: Her last conversations, May 9, The yellow Notebook – may1897)

Oh, had you but recognized the grace of God in Jesus Christ our Lord, and that very incarnation of His, wherein He assumed a human soul and body, you might have seemed the brightest example of grace! But what am I doing? I know it is useless to speak to a dead man – useless, at least, so far as regards you, but perhaps not in vain for those who esteem you highly, and love you on account of their love of wisdom or curiosity about those arts which you ought not to have learned; and these persons I address in your name. The grace of God could not have been more graciously commended to us than thus, that the only Son of God, remaining unchangeable in Himself, should assume humanity, and should give us the hope of His love, by means of the mediation of a human nature, through which we, from the condition of men, might come to Him who was so far off – the immortal from the mortal; the unchangeable from the changeable; the just from the unjust; the blessed from the wretched. And, as He had given us a natural instinct to desire blessedness and immortality, He Himself continuing to be blessed; but assuming mortality, by enduring what we fear, taught us to despise it, that what we long for He might bestow upon us. But in order to your acquiescence in this truth, it is lowliness that is requisite, and to this it is extremely difficult to bend you. (Saint Augustine of Hippo. The City of God, Book X, Ch. 29)

But he bestows a greater grace; therefore, it says: ‘God resists the proud, but gives grace to the humble.’ So submit yourselves to God. Resist the devil, and he will flee from you. Draw near to God, and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you of two minds. (Jas 4:6 – 8)

It seems to me that God wishes you to place the eyes of the understanding on the beauty of the soul, and on the Blood of his Son; by which Blood He washed the face of our soul: and you are the minister of It. […] The treasure of the Church is the Blood of Christ, given as the price for the soul. […] It is better, then, to let the gold of temporal things be lost than the gold of spiritual things. […] Open, open wide the eye of understanding with hunger and desire for the salvation of souls, to consider two evils: the evil of grandeur, dominion and temporal goods that you think you should conquest, and the evil of seeing the loss of grace in souls. From this you will see that you are much more obliged to reconquer souls. (Saint Catherine of Siena. Letter 209 to Gregory XI)

Be you manful for me, in the holy fear of God; wholly exemplary in your words, your habits, and all your deeds. Let all shine clear in the sight of God and me; as a light placed in the candlestick, of Holy Church, to which looks and should look all the Christian people. (Saint Catherine of Siena. Letter 270 to Urban VI, pg 335)

This see of Saint Peter always remains unblemished by any error, in accordance with the divine promise of our Lord and Saviour to the prince of his disciples: I have prayed for you that your faith may not fail; and when you have turned again, strengthen your brethren (Lk 22:32). This gift of truth and never-failing faith was therefore divinely conferred on Peter and his successors in this see so that they might discharge their exalted office for the salvation of all, and so that the whole flock of Christ might be kept away by them from the poisonous food of error and be nourished with the sustenance of heavenly doctrine. (Vatican Council I. Session IV, Apostolic constitution Pastor aeternus, Ch. 4, no. 6-7, July 18,1870)