Galatians 3:7

1. But that our faith was also prefigured in Abraham, and that he was the patriarch of our faith, and, as it were, the prophet of it, the apostle has very fully taught, when he says in the Epistle to the Galatians: “He therefore that ministereth to you the Spirit, and worketh miracles among you, [doeth he it] by the works of the law, or by the hearing of faith? Even as Abraham believed God, and it was accounted unto him for righteousness. Know ye therefore, that they which are of faith, the same are the children of Abraham. But the Scripture, foreseeing that God would justify the heathen through faith, announced beforehand unto Abraham, that in him all nations should be blessed. …

For he remembered that the time was come of which the Psalm spake, “Let us break their bands asunder, and cast off their yoke from us;” since the time when “the nations became tumultuous, and the people imagined vain counsels;” when “the kings of the earth stood up, and the rulers were gathered together against the Lord, and against His Christ,” in order that thenceforward man might be justified by the liberty of faith, not by servitude to the law, “because the just shall live by his faith.” Now, although the prophet Habakkuk first said this, yet you have the apostle here confirming the prophets, even as Christ did. The object, therefore, of the faith whereby the just man shall live, will be that same God to whom likewise belongs the law, by doing which no man is justified. …

But let us proceed with our inquiry into some eminent chief fathers of our origin: for there are some to whom our monogamist parents Adam and Noah are not pleasing, nor perhaps Christ either. To Abraham, in fine, they appeal; prohibited though they are to acknowledge any other father than God. Grant, now, that Abraham is our father; grant, too, that Paul is. “In the Gospel,” says he, “I have begotten you.” Show yourself a son even of Abraham. For your origin in him, you must know, is not referable to every period of his life: there is a definite time at which he is your father. …

4. 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. …

In Isaiah: “And if ye will not believe, neither will ye understand.” Also the Lord in the Gospel: “For if ye believe not that I am He, ye shall die in your sins.” Moreover, that righteousness should subsist by faith, and that in it was life, was predicted in Habakkuk: “Now the just shall live by faith of me.” Hence Abraham, the father of the nations, believed; in Genesis: “Abraham believed in God, and it was counted unto him for righteousness.” In like manner, Paul to the Galatians: “Abraham believed in God, and it was counted unto him for righteousness. Ye know, therefore, that they which are of faith, the same are children of Abraham. But the Scripture, foreseeing that God justifieth the heathens by faith, foretold to Abraham that all nations should be blessed in him. Therefore they who are of faith are blessed with faithful Abraham.”

Ver. 7 . “Know therefore, that they which be of faith, the same are sons of Abraham.” Which he proves by ancient testimony thus: