What is ‘The deposit’? That which has been entrusted to you, not that which you have yourself devised: a matter not of wit, but of learning; not of private adoption, but of public tradition; a matter brought to you, not put forth by you, wherein you are bound to be not an author but a keeper, not a teacher but a disciple, not a leader but a follower. ‘Keep the deposit.’ Preserve the talent of Catholic Faith inviolate, unadulterate. That which has been entrusted to you, let it continue in your possession, let it be handed on by you. You have received gold; give gold in turn. Do not substitute one thing for another. Do not for gold impudently substitute lead or brass. Give real gold, not counterfeit. (Saint Vincent of Lerins. Commonitory, Ch. 22, no. 53)

Thus faith comes from what is heard, and what is heard comes through the word of Christ. (Rom 10:17)

Two things are requisite for faith. First, that the things which are of faith should be proposed to man: this is necessary in order that man believe anything explicitly. The second thing requisite for faith is the assent of the believer to the things which are proposed to him. Accordingly, as regards the first of these, faith must needs be from God. Because those things which are of faith surpass human reason, hence they do not come to man’s knowledge, unless God reveal them. To some, indeed, they are revealed by God immediately, as those things which were revealed to the apostles and prophets, while to some they are proposed by God in sending preachers of the faith, according to Rm 10:15: ‘How shall they preach, unless they be sent?’
As regards the second, viz. man’s assent to the things which are of faith, we may observe a twofold cause, one of external inducement, such as seeing a miracle, or being persuaded by someone to embrace the faith: neither of which is a sufficient cause, since of those who see the same miracle, or who hear the same sermon, some believe, and some do not. Hence we must assert another internal cause, which moves man inwardly to assent to matters of faith.
The Pelagians held that this cause was nothing else than man’s free-will: and consequently they said that the beginning of faith is from ourselves, inasmuch as, to wit, it is in our power to be ready to assent to things which are of faith, but that the consummation of faith is from God, Who proposes to us the things we have to believe. But this is false, for, since man, by assenting to matters of faith, is raised above his nature, this must needs accrue to him from some supernatural principle moving him inwardly; and this is God. Therefore faith, as regards the assent which is the chief act of faith, is from God moving man inwardly by grace. (Saint Thomas Aquinas. Summa Theologica II-II, q. 6, a. 1)

Faith is a personal act − the free response of the human person to the initiative of God who reveals himself. But faith is not an isolated act. No one can believe alone, just as no one can live alone. You have not given yourself faith as you have not given yourself life. The believer has received faith from others and should hand it on to others. Our love for Jesus and for our neighbour impels us to speak to others about our faith. Each believer is thus a link in the great chain of believers. I cannot believe without being carried by the faith of others, and by my faith I help support others in the faith. (Catechism of the Catholic Church, no. 166)

The Church, ‘the pillar and bulwark of the truth’, faithfully guards ‘the faith which was once for all delivered to the saints’. She guards the memory of Christ’s words; it is she who from generation to generation hands on the apostles’ confession of faith. (1Tim 3:15; Jude 3) As a mother who teaches her children to speak and so to understand and communicate, the Church our Mother teaches us the language of faith in order to introduce us to the understanding and the life of faith. (Catechism of the Catholic Church, no. 171)

To obey (from the Latin ob-audire, to ‘hear or listen to’) in faith is to submit freely to the word that has been heard, because its truth is guaranteed by God, who is Truth itself. (Catechism of the Catholic Church, no. 144)

Faith demands to be passed on: it was not given to us merely for ourselves, for the personal salvation of our own souls, but for others, for this world and for our time. (Benedict XVI. Homily for the Episcopal ordination of five new Bishops, September 12, 2009)

‘How do we acquire a living faith, a truly Catholic faith, a faith that is practical, lively and effective?’ Faith, ultimately, is a gift. Consequently, the first condition is to let ourselves be given something, not to be self-sufficient or do everything by ourselves – because we cannot -, but to open ourselves in the awareness that the Lord truly gives. It seems to me that this gesture of openness is also the first gesture of prayer: being open to the Lord’s presence and to his gift. This is also the first step in receiving something that we do not have, that we cannot have with the intention of acquiring it all on our own. We must make this gesture of openness, of prayer – give me faith, Lord! – with our whole being. We must enter into this willingness to accept the gift and let ourselves, our thoughts, our affections and our will, be completely immersed in this gift. Here, I think it is very important to stress one essential point: no one believes purely on his own. . The Creed is always a shared act, it means letting ourselves be incorporated into a communion of progress, life, words and thought. We do not ‘have’ faith, in the sense that it is primarily God who gives it to us. Nor do we ‘have’ it either, in the sense that it must not be invented by us. We must let ourselves fall, so to speak, into the communion of faith, of the Church. Believing is in itself a Catholic act. It is participation in this great certainty, which is present in the Church as a living subject. (Benedict XVI. Meeting with the members of the Roman clergy, March 2. 2006)

The other thing concerns the fact that we ourselves cannot invent faith, composing it with ‘sustainable’ pieces, but we believe together with the Church. (Benedict XVI. Address to the Bishops of Switzerland, November 7, 2006)

Faith is not a product of our thought or our reflection; it is something new that we cannot invent but only receive as a gift, as a new thing produced by God. (Benedict XVI. General audience, December 10, 2008)

If anyone shall have said that divine revelation cannot be made credible by external signs, and for this reason men ought to be moved to faith by the internal experience alone of each one, or by private inspiration: let him be anathema. (Denzinger-Hünermann 3033. Vatican Council I, Dogmatic constitution Dei Filius, no. 3)

The Church, though dispersed throughout the whole world, even to the ends of the earth, has received from the apostles and their disciples this faith […] the Church, having received this preaching and this faith, although scattered throughout the whole world, yet, as if occupying but one house, carefully preserves it. She also believes these points [of doctrine] just as if she had but one soul, and one and the same heart, and she proclaims them, and teaches them, and hands them down, with perfect harmony, as if she possessed only one mouth. For, although the languages of the world are dissimilar, yet the import of the tradition is one and the same. (Saint Irenaeus of Lyons. Against heresies, I, 10, 1−2)

[Condemned doctrine] The dogmas which the Church professes as revealed are not truths fallen from heaven, but they are a kind of interpretation of religious facts, which the human mind by a laborious effort prepared for itself. (Denzinger-Hünermann 3422. Pius X, Decree of the Holy Office, Lamentabili, July 3, 1907)

I hold most certainly and profess sincerely that faith is not a blind religious feeling bursting forth from the recesses of the subconscious, unformed morally under the pressure of the heart and the impulse of the will, but the true assent of the intellect to the truth received extrinsically ex auditu, whereby we believe that what has been said, attested, and revealed by the personal God, our Creator and Lord, to be true on account of the authority of God the highest truth. (Denzinger-Hünermann 3542. Pius X, Motu proprio, Sacrorum antistitum, September 1, 1901)

Religion, whether natural or supernatural, must, like every other fact, admit of some explanation. But when Natural theology has been destroyed, the road to revelation closed through the rejection of the arguments of credibility, and all external revelation absolutely denied, it is clear that this explanation will be sought in vain outside man himself. It must, therefore, be looked for in man; and since religion is a form of life, the explanation must certainly be found in the life of man. Hence the principle of religious immanence is formulated. […] Therefore, since God is the object of religion, we must conclude that faith, which is the basis and the foundation of all religion, consists in a sentiment which originates from a need of the divine. (Pius X. Encyclical Pascendi dominici gregis, no. 7, September 8, 1907)

Should anyone ask how it is that this need of the divine which man experiences within himself grows up into a religion, the Modernists reply thus: Science and history, they say, are confined within two limits, the one external, namely, the visible world, the other internal, which is consciousness. When one or other of these boundaries has been reached, there can be no further progress, for beyond is the unknowable. In presence of this unknowable, whether it is outside man and beyond the visible world of nature, or lies hidden within in the subconsciousness, the need of the divine, according to the principles of Fideism, excites in a soul with a propensity towards religion a certain special sentiment, without any previous advertence of the mind: and this sentiment possesses, implied within itself both as its own object and as its intrinsic cause, the reality of the divine, and in a way unites man with God. It is this sentiment to which Modernists give the name of faith, and this it is which they consider the beginning of religion. (Pius X. Encyclical Pascendi dominici gregis, no. 7, September 8, 1907)

But we have not yet come to the end of their philosophy, or, to speak more accurately, their folly. For Modernism finds in this sentiment not faith only, but with and in faith, as they understand it, revelation, they say, abides. For what more can one require for revelation? Is not that religious sentiment which is perceptible in the consciousness revelation, or at least the beginning of revelation? Nay, is not God Himself, as He manifests Himself to the soul, indistinctly it is true, in this same religious sense, revelation? And they add: Since God is both the object and the cause of faith, this revelation is at the same time of God and from God; that is, God is both the revealer and the revealed. Hence, Venerable Brethren, springs that ridiculous proposition of the Modernists, that every religion, according to the different aspect under which it is viewed, must be considered as both natural and supernatural. Hence it is that they make consciousness and revelation synonymous. Hence the law, according to which religious consciousness is given as the universal rule, to be put on an equal footing with revelation, and to which all must submit, even the supreme authority of the Church, whether in its teaching capacity, or in that of legislator in the province of sacred liturgy or discipline. (Pius X. Encyclical Pascendi dominici gregis, no. 8-9, September 8, 1907)

Though they express astonishment themselves, no one can justly be surprised that We number such men among the enemies of the Church, if, leaving out of consideration the internal disposition of soul, of which God alone is the judge, he is acquainted with their tenets, their manner of speech, their conduct. Nor indeed will he err in accounting them the most pernicious of all the adversaries of the Church. For as We have said, they put their designs for her ruin into operation not from without but from within; hence, the danger is present almost in the very veins and heart of the Church, whose injury is the more certain, the more intimate is their knowledge of her. Moreover they lay the axe not to the branches and shoots, but to the very root, that is, to the faith and its deepest fibres. And having struck at this root of immortality, they proceed to disseminate poison through the whole tree, so that there is no part of Catholic truth from which they hold their hand, none that they do not strive to corrupt. (Pius X. Encyclical Pascendi dominici gregis, no. 3, September 8, 1907)

This being the case, he is the true and genuine Catholic who loves the truth of God, who loves the Church, who loves the Body of Christ, who esteems divine religion and the Catholic Faith above everything, above the authority, above the regard, above the genius, above the eloquence, above the philosophy, of every man whatsoever; who sets light by all of these, and continuing steadfast and established in the faith, resolves that he will believe that, and that only, which he is sure the Catholic Church has held universally and from ancient time; but that whatsoever new and unheard-of doctrine he shall find to have been furtively introduced by some one or another, besides that of all, or contrary to that of all the saints, this, he will understand, does not pertain to religion, but is permitted as a trial. (Saint Vincent of Lerins. Commonitory, Ch. 20, no. 48)

But some one will say, perhaps, Shall there, then, be no progress in Christ’s Church? Certainly; all possible progress. For what being is there, so envious of men, so full of hatred to God, who would seek to forbid it? Yet on condition that it be real progress, not alteration of the faith. For progress requires that the subject be enlarged in itself, alteration, that it be transformed into something else. The intelligence, then, the knowledge, the wisdom, as well of individuals as of all, as well of one man as of the whole Church, ought, in the course of ages and centuries, to increase and make much and vigorous progress; but yet only in its own kind; that is to say, in the same doctrine, in the same sense, and in the same meaning. […] In like manner, it behooves Christian doctrine to follow the same laws of progress, so as to be consolidated by years, enlarged by time, refined by age, and yet, withal, to continue uncorrupt and unadulterate, complete and perfect in all the measurement of its parts, and, so to speak, in all its proper members and senses, admitting no change, no waste of its distinctive property, no variation in its limits. (Saint Vincent of Lerins. Commonitory, Ch. 20, no. 54.56)

How much more honorable a creed is that which was taught by the holy and truthful angels, uttered by the prophets who were moved by God’s Spirit, preached by Him who was foretold as the coming Saviour by His forerunning heralds, and by the apostles whom He sent forth, and who filled the whole world with the gospel? (Saint Augustine of Hippo. The City of God, Book X, ch. 30)