His last clause runs thus: “I have kept the faith.” But he who says this is the same who declares in another passage, “I have obtained mercy that I might be faithful.” He does not say, “I obtained mercy because I was faithful,” but “in order that I might be faithful,” thus showing that even faith itself cannot be had without God’s mercy, and that it is the gift of God. This he very expressly teaches us when he says, “For by grace are ye saved through faith, and that not of yourselves; it is the gift of God.” They might possibly say, “We received grace because we believed;” as if they would attribute the faith to themselves, and the grace to God. Therefore, the apostle having said, “Ye are saved through faith,” added,” And that not of yourselves, but it is the gift of God.” And again, lest they should say they deserved so great a gift by their works, he immediately added, “Not of works, lest any man should boast.” Not that he denied good works, or emptied them of their value, when he says that God renders to every man according to his works; but because works proceed from faith, and not faith from works. Therefore it is from Him that we have works of righteousness, from whom comes also faith itself, concerning which it is written, “The just shall live by faith.”
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 1, vol. 5 (Schaff, 1887), public domain (Public domain).