Augustine in His Own Words
that person seek in us, His members, those merits which preceded our multiple rebirth. For that birth was not given to Christ as recompense, but rather was given so that He should be born of the Spirit and the Virgin, apart from all the bonds of sin. And likewise our being born again by water and the Spirit is not a recompense for any merit but is freely given to us. And if faith has led us to the bath of rebirth, we ought not for that reason to think that we have first given something to God so that our saving rebirth might be given to us in return. For the One who has made us believe in Christ is the One who made for us the Christ in whom we believe. He who made in human beings the beginning (principium) and the perfection of their faith in Jesus, made the man Jesus "the author (principem) and perfecter of faith" (Heb 12:2), for this is what He is called, as you know, in the Epistle to the Hebrews.102
Making Progress
Augustine recognized that his thinking on grace and on many other issues, both large and small, had shifted over time. At the very moment when he was responding to Prosper's and Hilary's concerns, he was also in the process of reviewing his vast output and his long career as an author and recording his reflections in his Reconsiderations. Here he reflects on his search. From The Gift of Perseverance:
(21.55) For at this moment I am writing a treatise in which I have begun to reconsider my works103 in order to show that I have not followed myself in all matters, but rather I think that, through the mercy of God, I have made progress in writing and did not begin at the point of perfection. For that matter, I would be speaking with more arrogance than truth if I were to say that even now, at my present age, I have arrived at perfection, in writing without any errors. But it makes a difference to what extent and in what matters one has erred, and how easily one corrects one's error, or with what obstinacy one attempts to defend it. Certainly there is high hope for a man, if the last day of this life finds him making such progress that whatever was lacking in his progress is supplied to him, and that he is judged as worthy to be perfected rather than punished.104
102. De praedestinatione sanctorum 15.30–31 (BA 24:252–56); my trans., based on Mourant and Collinge, FOTC 86:253–56. On this theme, see Réné Bernard, "La prédestination au Christ total selon saint Augustin," Recherches augustiniennes 3 (1965): 1–58; on its place within Augustine's broader Christology and theology of grace, see Hombert, Gloria Gratiae, 439–508.
103. "Reconsider my works": Augustine is referring to retr. 104. De dono perseverantiae 21.55 (BA 24:736); trans. Mourant and Collinge, FOTC 86:326.