Irenaeus: Demonstration of the Apostolic Preaching

35. Moreover He fulfilled the promise made to Abraham, which God had promised him, to make his seed as the stars of heaven. For this Christ did, who was born of the Virgin who was of Abraham’s seed, and constituted those who have faith in Him lights in the world, ^[1] and by the same faith with Abraham justified the Gentiles. For Abraham believed God, and it was counted unto him for righteousness. (cf. Rom. iv. 3) In like manner we also are justified by faith in God: for the just shall live by faith. Now not by the law is the promise to Abraham, but by faith: for Abraham was justified by faith: and for a righteous man the law is not made. In like manner we also are justified not by the law, but by faith, which is witnessed to in the law and in the prophets, whom the Word of God presents to us.