Augustine of Hippo, On the Predestination of the Saints Chapter 32: The Twofold Calling

Chapter 32 [XVI.]—The Twofold Calling.

God indeed calls many predestinated children of His, to make them members of His only predestinated Son,—not with that calling with which they were called who would not come to the marriage, since with that calling were called also the Jews, to whom Christ crucified is an offence, and the Gentiles, to whom Christ crucified is foolishness; but with that calling He calls the predestinated which the apostle distinguished when he said that he preached Christ, the wisdom of God and the power of God, to them that were called, Jews as well as Greeks. For thus he says “But unto them which are called,” in order to show that there were some who were not called; knowing that there is a certain sure calling of those who are called according to God’s purpose, whom He has foreknown and predestinated before to be conformed to the image of His Son. And it was this calling he meant when he said, “Not of works, but of Him that calleth; it was said unto her, That the elder shall serve the younger.” Did he say, “Not of works, but of him that believeth”? Rather, he actually took this away from man, that he might give the whole to God. Therefore he said, “But of Him that calleth,”—not with any sort of calling whatever, but with that calling wherewith a man is made a believer.