Augustine writes to Prosper and Hilary against the claim that the beginning of faith arises from human initiative. He argues that predestination precedes holiness and prepares every saving gift: faith, its growth, and final perseverance. God does not elect people because he foresees their merits; rather, effective grace creates faith, while the differing destinies of infants and Christ’s predestination as Son display the gratuitous character of election. The reasons why mercy is given to some and withheld from others remain inscrutable, and no one should be judged by hypothetical future sins or merits.

Book II interprets the Lord’s Prayer as a doctrine of grace: “Your will be done” asks for conversion and holiness, “daily bread” for continued union with Christ, and the petitions for forgiveness and deliverance from evil deny that anyone is sinless in this life. Final perseverance, granted only at life’s end and especially evident in martyrdom, cannot be lost once given, though Christians must pray for it. Augustine maintains that predestination does not abolish preaching, exhortation, rebuke, prayer, or moral responsibility; human effort is the means through which God works. Pastors should preach the doctrine carefully, urging sinners to discipline rather than passive waiting, without declaring anyone rejected. The Church’s prayers for unbelievers and for believers’ perseverance testify that conversion, faithful living, and perseverance are divine gifts. Augustine closes by directing all glory to God and presenting Christ’s predestination as the supreme pattern of gratuitous grace.