Romans 3:30

By "the circumcised" Paul means the Jews who have been justified by their faith in the promise and who believe that Jesus is the Christ whom God had promised in the law. By "the uncircumcised" he means the Gentiles who have been justified with God …

For "it is one God which justifies the circumcision by faith, and the uncircumcision through faith;" in which clauses there is no real difference in the sense, as if the phrase "by faith" meant one thing, and "through faith" another, but only a variety of expression. For in one passage, when speaking of the Gentiles,—that is, of the uncircumcision,—he says, "The Scripture, foreseeing that God would justify the heathen by faith;" and again, in another, when speaking of the circumcision, to which he himself belonged, he says, "We who are Jews by nature, and not sinners of the Gentiles, knowing that a man is not justified by the works of the law, but through faith in Jesus Christ, even we believed in Jesus Christ."

For all things had entered upon a new phase, the Word arranging after a new manner the advent in the flesh, that He might win back to God that human nature (hominem) which had departed from God; and therefore men were taught to worship God after a new fashion, but not another god, because in truth there is but "one God, who justifieth the circumcision by faith, and the uncircumcision through faith."

Thus then does the Lord plainly show that it was the true Lord and the one God who had been set forth by the law; for Him whom the law proclaimed as God, the same did Christ point out as the Father, whom also it behoves the disciples of Christ alone to serve. By means of the statements of the law, He put our adversary to utter confusion; and the law directs us to praise God the Creator (Demiurgum), and to serve Him alone. Since this is the case, we must not seek for another Father besides Him, or above Him, since there is one God who justifies the circumcision by faith, and the uncircumcision through faith.

Hence he also fittingly adds in what follows: "Or is he the God of the Jews only? Is he not also of the Gentiles? Yes, of the Gentiles also. Since indeed there is one God, who justifies the circumcision from faith, and the uncircumcision through faith." For those who would have the God of the Jews to be one and the God of the Gentiles another — that is, one God of the Law and another of the Gospels — the reply on this point will be narrow and confining enough, since the apostle Paul gives his verdict abundantly enough when he not only says that there is one God of Jews and of Gentiles, but also adds that it is one and the same God who justifies the circumcision from faith and the uncircumcision through faith. And if they should wish to take "circumcision" by way of allegory, so as to say that by this word he called all the holy and spiritual ones, they will at once find a stumbling block in what follows. For if he called the holy ones — or, as they name them, the spiritual ones — "circumcision," it follows that by "uncircumcision" he meant sinners, whom they call "animal" (of the soul). And how will it be fitting that the good God should justify spiritual and animal alike? For them, then, there will be an inextricable knot in these words of the Apostle. But according to us, who say that "circumcision" means those who have believed from among the Jews, and "uncircumcision" no less means those who have been called from among the Gentiles to the faith, the exposition will be plain and easy. For it is one and the same God who justifies believers from either people, not by the privilege of circumcision or of uncircumcision, but by the regard for faith alone. There remains also the difference of a single syllable, in which the Apostle seems to have varied his expression. […]