Here I would like to indicate one of them: the option or love of preference for the poor. This is an option, or a special form of primacy in the exercise of Christian charity, to which the whole tradition of the Church bears witness. (John Paul II. Encyclical Sollicitudo rei socialis, no. 42, December 30, 1987)

But he also wished to be near to those who, though rich in the goods of this world, were excluded from the community as ‘publicans and sinners’, for he had come to call them to conversion (cf. Lk 19:1-10; Mk 2:13-17). It is this sort of poverty, made up of detachment, trust in God, sobriety and a readiness to share, that Jesus declared blessed. (Congregation for the Doctrine of the Faith: Instruction Libertatis conscientia, no. 66, March 22, 1986)

He who oppresses the poor blasphemes his Maker, but he who is kind to the needy
glorifies him. (Prov 14:31)

Only, we were to be mindful of the poor, which is the very thing I was eager to do. (Gal 2:10)

There is no partiality with God. (Rom 2:11)

For the Lord of all shows no partiality, nor does he fear greatness, Because he himself made the great as well as the small, and he provides for all alike. (Wis 6:7)

The precept of detachment from riches is obligatory for entrance into the Kingdom of heaven. All Christ’s faithful are to ‘direct their affections rightly, lest they be hindered in their pursuit of perfect charity by the use of worldly things and by an adherence to riches which is contrary to the spirit of evangelical poverty’ (LG 4/ 3). […] “The Word speaks of voluntary humility as ‘poverty in spirit’; the Apostle gives an example of God’s poverty when he says: ‘For your sakes he became poor’” (St. Gregory of Nyssa, De beatitudinibus 1; cf. 2Cor 8:9). (Catechism of the Catholic Church, no. 2544-2546)

Since among some learned men it often happens that doubt is again raised as to whether should be branded as heretical to affirm persistently that our Redeemer and Lord Jesus Christ and His apostles did not possess anything either in particular or even in common, even though there are different and adverse opinions on that question, we, in a desire to put an end to this controversy, declare on the advice of our brethren by this perpetual edict that a persistent assertion of this kind shall henceforth be branded as erroneous and heretical, since it expressly contradicts Sacred Scripture, which in many passages asserts that they did have some possessions; and since with regard to the aforementioned it openly submits that Sacred Scripture itself, by which surely the articles of orthodox faith are approved, contains a ferment of falsehood and consequently, in so far as in it lies, completely voiding the faith of Scripture it renders the Catholic faith, by destroying its approval, doubtful and uncertain. (Denzinger-Hünermann 930. John XXII, Edict Cum inter nonnullos, November 13, 1323)

But the Lord chose afterwards orators also; but they would have been proud, if He had not first chosen fishermen; He chose rich men; but they would have said that on account of their riches they had been chosen, unless at first He had chosen poor men. (Saint Augustine. Expositions on the Book of Psalms, 66, no. 4)

In its positive meaning the ‘Church of the poor’ signifies the preference given to the poor, without exclusion, whatever the form of their poverty, because they are preferred by God. (Congregation for the Doctrine of the Faith, Instruction Libertatis nuntius, no. 9, October 6, 2007)

Hence, ‘the preferential option for the poor is implicit in the Christological faith in the God who became poor for us, so as to enrich us with his poverty.’ This option arises out of our faith in Jesus Christ, God made man, who has become our brother (cf. Heb 2:11-12). Yet it is neither exclusive nor excluding. (V General Conference of the Bishops of Latin America and the Caribbean, CELAM, Aparecida Document, no. 392, June 29, 2007)

We also understand that true human promotion cannot be reduced to particular aspects: ‘It must be well rounded; it must foster the development of each man and of the whole man’(Gaudium et Spes 76). (V General Conference of the Bishops of Latin America and the Caribbean, CELAM, Aparecida Document, no. 399, June 29, 2007)

The different theologies of liberation are situated between the ‘preferential option for the poor’, forcefully reaffirmed without ambiguity after Medellin at the Conference of ‘Puebla’ (cf. ‘Gaudium et spes’, n.39; Pius XI, Quadragesimo anno) on the one hand, and the temptation to reduce the Gospel to an earthly gospel on the other. (Congregation for the Doctrine of the Faith, Instruction Libertatis nuntius, no. 5, October 6, 2007)

The special option for the poor, far from being a sign of particularism or sectarianism, manifests the universality of the Church’s being and mission. This option excludes no one. This is the reason why the Church cannot express this option by means of reductive sociological and ideological categories which would make this preference a partisan choice and a source of conflict. (Congregation for the Doctrine of the Faith, Instruction Libertatis Conscientia, no. 68, March 22, 1986)

For man’s horizons are not limited only to the temporal order; while living in the context of human history, he preserves intact his eternal vocation. (Vatican Council II, Pastoral Constitution, Gaudium et spes, no. 76, December 7, 1965)

The true worth and nobility of man lie in his moral qualities, that is, in virtue; that virtue is, moreover, the common inheritance of men, equally within the reach of high and low, rich and poor; and that virtue, and virtue alone, wherever found, will be followed by the rewards of everlasting happiness. (Leo XIII. Encyclical Rerum novarum, no. 24, May 15, 1891)

The great mistake made in regard to the matter now under consideration is to take up with the notion that class is naturally hostile to class, and that the wealthy and the working men are intended by nature to live in mutual conflict. So irrational and so false is this view that the direct contrary is the truth. Just as the symmetry of the human frame is the result of the suitable arrangement of the different parts of the body, so in a State is it ordained by nature that these two classes should dwell in harmony and agreement, so as to maintain the balance of the body politic. (Leo XIII. Encyclical Rerum novarum, no. 19, May 15, 1891)

‘Blessed’, it says, ‘are the poor’. Not all the poor are blessed; for poverty is of itself neutral: there can be evil or good people who are poor. (Saint Ambrose. Treatise on the Gospel of Saint Luke, bk.V, no. 53: PL 15, 1650)

In truth, not all poverty is holy, nor is all richness criminal. (Saint Ambrose. Treatise on the Gospel of Saint Luke, bk.VIII, no. 13: PL 15, 1769)

It is necessary to know that there is no sin in goods; but in those who do not know how to use them; because riches may serve as a hindrance for the evil, or as a great help for the virtue of the good. (Saint Ambrose. Treatise on the Gospel of Saint Luke, bk.VIII, no. 85: PL 15, 1791)

He [the Lord] calls rich the one who yearns for temporal goods and takes pride in them. Contrasting to these rich are the poor of spirit, to whom the kingdom of heaven belongs […] It must be understood that amongst the number of those [the rich] are counted even those who, although not having riches, are all caught up in the desire to have them. (Saint Augustine. Quaestiones in Evangelium secundum Lucam, II, no. 47)

The same holds good also in the case of poverty. For it compels the soul to desist from necessary things, I mean contemplation and from pure sinlessness, forcing him, who has not wholly dedicated himself to God in love, to occupy himself about provisions; as, again, health and abundance of necessaries keep the soul free and unimpeded, and capable of making a good use of what is at hand. (Saint Clement of Alexandria. Book IV, Ch. 5)

Therefore, riches are good, to the extent that they advance the practice of virtue, but if this measure is departed from, so that the practice of virtue is hindered by them, then they are not to be numbered among goods, but among evils. […] So, poverty is praiseworthy according as it frees man from the vices in which some are involved through riches. Moreover, in so far as it removes the solicitude which arises from riches, it is useful to some, namely, those disposed to busy themselves with better things. (Saint Thomas Aquinas. Summa contra Gentiles. bk. III, ch. 133, nos. 1,3)

And since neither riches, nor poverty, nor any external thing is in itself man’s good, but they are only so as they are ordered to the good of reason, nothing prevents a vice from arising out of any of them, when they do not come within man’s use in accord with the rule of reason. Yet they are not to be judged evil in themselves; rather, the use of them may be evil. (Saint Thomas Aquinas. Summa contra Gentiles, bk. III, ch. 134, no. 6)

Now if I demand this of you, it will seem perhaps to most of you grievous and burdensome; because therefore of your infirmity I speak not of such perfection, but desire you not to be nailed to riches; and as I, because of the infirmity of the many, retire somewhat from (demanding) the excess of virtue, I desire that you do so and much more on the side of vice. I blame not those who have houses, and lands, and wealth, and servants, but wish them to possess these things in a safe and becoming way. And what is ‘a becoming way’? As masters, not as slaves; so that they rule them, be not ruled by them; that they use, not abuse them. (Saint John Chrysostom. Homiles on the Gospel of Saint John, Homily 19, no. 3)

And the Word became flesh and made his dwelling among us, and we saw his glory, the glory as of the Father’s only Son, full of grace and truth. From his fullness we have all received, grace in place of grace. (Jn 1:14.16)

For through faith you are all children of God in Christ Jesus. For all of you who were baptized into Christ have clothed yourselves with Christ. There is neither Jew nor Greek, there is neither slave nor free person, there is not male and female; for you are all one in Christ Jesus. (Gal 3:26-28)

He is the head of the body, the church. (Col 1:18)

The sacraments of the Church derive their power specially from Christ’s Passion, the virtue of which is in a manner united to us by our receiving the sacraments. It was in sign of this that from the side of Christ hanging on the Cross there flowed water and blood, the former of which belongs to Baptism, the latter to the Eucharist, which are the principal sacraments. (Saint Thomas Aquinas. Summa Theologica III, q. 62, a.5)

The head and members are as one mystic person; and therefore Christ’s satisfaction belongs to all the faithful as being His members. (Saint Thomas Aquinas. Summa Theologica III, q. 48, a.2, ad 1)

Grace is a participation in the life of God. It introduces us into the intimacy of Trinitarian life: by Baptism the Christian participates in the grace of Christ, the Head of his Body. As an ‘adopted son’ he can henceforth call God ‘Father’, in union with the only Son. He receives the life of the Spirit who breathes charity into him and who forms the Church. (Catechism of the Catholic Church, no. 1997)

Our Redeemer has shown Himself to be one with the Holy Church, which He has taken to Himself, for of Him it is said, Who is the Head of us all (Eph 4:15) and of the Church it is written, the Body of Christ, Which is the Church (Col 1: 24). (Gregory I, the Great. Preface, Vol. 1, 14: PL 75.525)

Let us rejoice, then, and give thanks that we are made not only Christians, but Christ. Do ye understand, brethren, and apprehend the grace of God upon us? Marvel, be glad, we are made Christ. For if He is the head, we are the members: the whole man is He and we. […] But above he had said, ‘Until we all come together into the unity of faith, and to the knowledge of the Son of God, to the perfect man, to the measure of the age of the fullness of Christ’ (Eph 4:14). The fullness of Christ, then, is head and members. Head and members, what is that? Christ and the Church. (Saint Augustine. Tractates on Saint John, Tractate 21, no. 8)

Incarnation derives from the Latin incarnatio. St Ignatius of Antioch — at the end of the first century — and, especially, St Irenaeus used this term in reflecting on the Prologue to the Gospel according to St John, in particular in the sentence ‘the Word became flesh’ (Jn 1:14). Here the word ‘flesh’, according to the Hebrew usage, indicates man in his whole self, the whole man, but in particular in the dimension of his transience and his temporality, his poverty and his contingency. This was in order to tell us that the salvation brought by God, who became man in Jesus of Nazareth, affects man in his material reality and in whatever situation he may be. God assumed the human condition to heal it from all that separates it from him, to enable us to call him, in his Only-Begotten Son, by the name of ‘Abba, Father’, and truly to be children of God. Saint Irenaeus stated: ‘For this is why the Word became man, and the Son of God became the Son of man: so that man, by entering into communion with the Word and thus receiving divine sonship, might become a son of God’ (Adversus Haereses, 3, 19, 1; cf. Catechism of the Catholic Church, n. 460). (Benedict XVI. General audience, January 9, 2013)

By communicating His Spirit, Christ made His brothers, called together from all nations, mystically the components of His own Body. In that Body the life of Christ is poured into the believers who, through the sacraments, are united in a hidden and real way to Christ who suffered and was glorified (cf. St. Thomas Aquinas. STh III, q. 62, a.5, ad1) (Vatican Council II, Lumen gentium, no. 7, November 21, 1964)

At this time, then (that is, at His baptism), He was pleased to prefigure His Church, in which those especially who are baptized receive the Holy Ghost (S. Aug. De. Trin. I, 15, c. 26). (Leo XIII. Encyclical Divinum illud munus, May 9, 1897)

Actually only those are to be included as members of the Church who have been baptized and profess the true faith, and who have not been so unfortunate as to separate themselves from the unity of the Body, or been excluded by legitimate authority for grave faults committed. ‘For in one spirit’ says the Apostle, ‘were we all baptized into one Body, whether Jews or Gentiles, whether bond or free’ (1Cor 12:13). As therefore in the true Christian community there is only one Body, one Spirit, one Lord, and one Baptism, so there can be only one faith (cf. Eph 4:5). And therefore, if a man refuse to hear the Church, let him be considered – so the Lord commands – as a heathen and a publican (cf. Mt 18:17). It follows that those who are divided in faith or government cannot be living in the unity of such a Body, nor can they be living the life of its one Divine Spirit. (Pius XII. Encyclical Mystici Corporis Christi, no. 21, June 29, 1943)

Thus, by degrees, came into existence the patrimony which the Church has guarded with religious care as the inheritance of the poor. Nay, in order to spare them the shame of begging, the Church has provided aid for the needy. The common Mother of rich and poor has aroused everywhere the heroism of charity, and has established congregations of religious and many other useful institutions for help and mercy, so that hardly any kind of suffering could exist which was not afforded relief. […] But no human expedients will ever make up for the devotedness and self sacrifice of Christian charity. Charity, as a virtue, pertains to the Church; for virtue it is not, unless it be drawn from the Most Sacred Heart of Jesus Christ; and whosoever turns his back on the Church cannot be near to Christ. (Leo XIII. Encyclical Rerum novarum, no. 30, May 15, 1891)

But, God forbid that the sons of the Catholic Church ever in any way be hostile to those who are not joined with us in the same bonds of faith and love; […] and they should especially endeavor to snatch them from the darkness of error in which they unhappily lie, and lead them back to Catholic truth and to the most loving Mother the Church, who never ceases to stretch out her maternal hands lovingly to them, and to call them back to her bosom so that, […] they may attain eternal salvation. (Denzinger 1678, Pius IX, Encyclical Quanto conficiamur moerore, August 10, 1863)

It is therefore primarily by her conduct and by her life that the Church will evangelize the world, in other words, by her living witness of fidelity to the Lord Jesus- the witness of poverty and detachment, of freedom in the face of the powers of this world, in short, the witness of sanctity. (Paul VI. Apostolic Exhortation Evangelii nuntiandi, no. 41, December 8, 1975)