Already in 1 Peter 1:1, the apostle had characterized his readers as “elect.” That term implied that God once chose them (before the foundation of the world, Ephesians 1:4) to be his, and later, through the preaching of the gospel, “called” them to faith (1 Peter 1:25). To say it in words borrowed from 1 Peter 1:3, as a child does not cause his own birth (but is dependent on the readiness of his mother), so the elect did not cause their own rebirth but were dependent on God’s call.
15 but as he who called you is holy, you also be holy in all your conduct,