Peter begins by praising God for the mercy of his saving grace. God has given his people an entirely new life through Jesus Christ. So new is this life that Peter employs the notion of rebirth, a notion used infrequently in Scripture despite its widespread use today. What sort of life does God give his people in their rebirth?
It is a life oriented toward the future. Those who are reborn have a hope that animates their present lives (1:3-5; cf. 1:13, 21; 3:5, 15). Accordingly, joy and exultation characterize the daily lives of Christians (1:6, 8, 9). Peter does not say that rebirth makes people happy, at least not in the way that word is commonly used. Peter does say that rebirth equips Christians with ability to see all of life in the light of the glory to be revealed when Christ returns.
The new life God gives in Christ is also a life of fulfillment, the fulfillment of all God's promises to Israel. What the prophets announced beforehand, what they anticipated in the sufferings and glories of the Messiah, is precisely that saving grace that has enlivened believers (1:10-12).
Peter does not, however, promise a life of ease. If God gives his people a life of hope, joy, certainty, and fulfillment, it is also a life subject to testing and trial. Saving grace comes through the Christ who suffered and then received glory (1:10-11). That same pattern, from present suffering to future glory, characterizes the life of those reborn. For that reason, just as he describes the joy and hope, he also describes the suffering that attends Christian life (1:6). Such suffering, however, serves as an aid to grace and becomes a basis for even greater joy and praise to God. In light of God's redemptive purposes, the sufferings of his people, like the fiery testing of gold, will prepare them for the glory that awaits them at Christ's return (1:7).
If Christians' sufferings are to serve this purpose, they must be true to their calling as God's people. Peter addresses the implications of that calling in the exhortations that comprise the bulk of his letter.