Gal 3:6

“If, then, God promised him the inheritance of the land, yet he did not receive it during all the time of his sojourn there, it must be, that together with his seed, that is, those who fear God and believe in Him, he shall receive it at the resurrection of the just. For his seed is the Church, which receives the adoption to God through the Lord, as John the Baptist said: "For God is able from the stones to raise up children to Abraham." Thus also the apostle says in the Epistle to the Galatians: "But ye, brethren, as Isaac was, are the children of the promise." And again, in the same Epistle, he plainly declares that they who have believed in Christ do receive Christ, the promise to Abraham thus saying, "The promises were spoken to Abraham, and to his seed. Now He does not say, And of seeds, as if [He spake] of many, but as of one, And to thy seed, which is Christ." And again, confirming his former words, he says, "Even as Abraham believed God, and it was accounted to him for righteousness. Know ye therefore, that they which are of faith are the children of Abraham. But the Scripture, fore-seeing that God would justify the heathen through faith, declared to Abraham beforehand, That in thee shall all nations be blessed. So then they which are of faith shall be blessed with faithful Abraham." Thus, then, they who are of faith shall be blessed with faithful Abraham, and these are the children of Abraham. Now God made promise of the earth to Abraham and his seed; yet neither Abraham nor his seed, that is, those who are justified by faith, do now receive any inheritance in it; but they shall receive it at the resurrection of the just. For God is true and faithful; and on this account He said, "Blessed are the meek, for they shall inherit the earth."”

“But how are we children of faith? and of whose faith, if not Abraham's? For since "Abraham believed God, and it was accounted to him for righteousness; " since, also, he deserved for that reason to be called "the father of many nations," whilst we, who are even more like him in believing in God, are thereby justified as Abraham was, and thereby also obtain life-since the just lives by his faith,-it therefore happens that, as he in the previous passage called us "sons of Abraham," since he is in faith our (common) father, so here also he named us "children of faith," for it was owing to his faith that it was promised that Abraham should be the father of (many) nations.”

“Accordingly it is patience which is both subsequent and antecedent to faith. In short, Abraham believed God, and was accredited by Him with righteousness; but it was patience which proved his faith, when he was bidden to immolate his son, with a view to (I would not say the temptation, but) the typical attestation of his faith.”

“Also in the priest Melchizedek we see prefigured the sacrament of the sacrifice of the Lord, according to what divine Scripture testifies, and says, "And Melchizedek, king of Salem, brought forth bread and wine." Now he was a priest of the most high God, and blessed Abraham. And that Melchizedek bore a type of Christ, the Holy Spirit declares in the Psalms, saying from the person of the Father to the Son: "Before the morning star I begat Thee; Thou art a priest for ever, after the order of Melchizedek; " which order is assuredly this coming from that sacrifice and thence descending; that Melchizedek was a priest of the most high God; that he offered wine and bread; that he blessed Abraham. For who is more a priest of the most high God than our Lord Jesus Christ, who offered a sacrifice to God the Father, and offered that very same thing which Melchizedek had offered, that is, bread and wine, to wit, His body and blood? And with respect to Abraham, that blessing going before belonged to our people. For if Abraham believed in God, and it was accounted unto him for righteousness, assuredly whosoever believes in God and lives in faith is found righteous, and already is blessed in faithful Abraham, and is set forth as justified; as the blessed Apostle Paul proves, when he says, "Abraham believed God, and it was accounted to him for righteousness. Ye know, then, that they which are of faith, these are the children of Abraham. But the Scripture, foreseeing that God would justify the Gentiles through faith, pronounced before to Abraham that all nations should be blessed in him; therefore they who are of faith are blessed with faithful Abraham." Whence in the Gospel we find that "children of Abraham are raised from stones, that is, are gathered from the Gentiles." And when the Lord praised Zacchaeus, He answered and said "This day is salvation come to this house, forasmuch as he also is a son of Abraham." In Genesis, therefore, that the benediction, in respect of Abraham by Melchizedek the priest, might be duly celebrated, the figure of Christ's sacrifice precedes, namely, as ordained in bread and wine; which thing the Lord, completing and fulfilling, offered bread and the cup mixed with wine, and so He who is the fulness of truth fulfilled the truth of the image prefigured.”

“Even the miracles done by themselves, he says, declare the power of Faith, but I shall attempt if you will suffer me to draw my proofs from ancient narratives also. Then, as they made great account of the Patriarch, he brings his example forward, and shows that he too was justified by Faith. And if he who was before grace, was justified by Faith, although plentiful in works, much more we. For what loss was it to him, not being under the Law? None, for his faith sufficed unto righteousness. The Law did not then exist, he says, neither does it now exist, any more than then. In disproving the need of the Law, he introduces one who was justified before the Law, lest an objection should also be made to him; for as then it was not yet given, so now, having been given, it was abrogated. And as they made much of their descent from Abraham, and feared lest, abandoning the Law, they should be considered strangers to his kin; Paul removes this fear by turning their argument against themselves, and proves that faith is especially concerned in connecting them with Abraham. He draws out this argument more at length in the Epistle to the Romans; however he urges it also here in, the words...”

“(Verse 6.) Just as Abraham believed God, and it was counted to him as righteousness. From this place until where it is written: Those who are of faith are blessed with faithful Abraham, Marcion erased from his Apostle. But what profit was there in embracing this, when the other things he left behind, his insanities, are opposed to it? Yet Abraham believed God, going out from his country into a land he did not know (Gen. 12 ff.): trusting that Sarah, who was ninety years old and barren, would give birth; and hearing the promise of God that his offspring would be called through Isaac, he offered Isaac as a sacrifice, and yet did not doubt the promise of the Lord. The faith is rightly considered to contribute to justice, the one who, having gone beyond the works of the Law, has deserved God not out of fear, but out of love.”

“Although, he says, you ought to have learned the power of faith primarily from the fact that you performed signs, yet if you also turn your attention to the forefather, about whom you speak so much, you will find that he too was justified by faith. And if one who lived before grace is justified by faith, then all the more must those who have been deemed worthy of grace hold fast to faith.”

“Having proved by experience the power of the faith and the insufficiency of the Law, the Apostle now proves the same things by authority and by reasons. First, he proves the power of the faith to justify; Secondly, in this he proves the insufficiency of the Law (v. 10). The first he proves by using a syllogism. Hence with respect to this he does three things: First, he proves the minor premise; Secondly, the major premise (v. 8); Thirdly, he draws the conclusion (v. 9). Concerning the first, he does two things: First, he proposes a certain authority from which he takes the minor; Secondly, he concludes the minor (v. 7). He says therefore: Truly, justice and the Holy Spirit come from faith, "As it is written" in Genesis (15:6) and mentioned again in Romans (4:3): "Abraham believed God and it was reputed to him unto justice." Here it should be noted that justice consists in paying a debt. Now man is indebted to God and to himself and to his neighbor. But it is on account of God that he owes something to himself and his neighbor. Therefore the highest form of justice is to render to God what is God's. For if you render to yourself or your neighbor what you owe and do not do this for the sake of God, you are more perverse than just, since you are putting your end in man. Now, whatever is in man is from God, namely, intellect and will and the body itself, albeit according to a certain order; because the lower is ordained to the higher, and external things to internal, namely, to the good of the soul. Furthermore, the highest thing in man is his mind. Therefore the first element of justice in a man is that a man's mind be subjected to God, and this is done by faith: "Bringing into captivity every understanding unto the obedience of Christ" (2 Cor 10:5). Therefore in all things it must be said that God is the first principle in justice and that whosoever gives to God, namely, the greatest thing that lies in him by submitting the mind to Him, such a one is fully just: "Whosoever are led by the Spirit of God, they are the sons of God" (Rom 8:14). And hence he says, Abraham believed God, i.e., submitted his mind to God by faith: "Believe God, and he will recover thee: and direct thy way, and trust in him" (Sir 2:6); and further on (2:8): "Ye that fear the Lord believe him," "and it was reputed to him unto justice," i.e., the act of faith and faith itself were for him, as for everyone else, the sufficient cause of justice. It is reputed to him unto justice by men exteriorly, but interiorly it is wrought by God, Who justifies them that have the faith. This he does by remitting their sins through charity working in them.”