A Call to Holiness
Peter turns hope into command by urging his readers to prepare their minds, remain sober, and fix their hope entirely on the grace to be brought at Christ's revelation. As obedient children they must no longer be shaped by the passions of their former ignorance. Instead, the holiness of the God who called them becomes the pattern for all they do, reinforced by the scriptural command, "Be holy, because I am holy." The paragraph shows that future grace creates present moral seriousness.
T13herefore prepare your minds for action. Be sober-minded. Set your hope fully on the grace to be given you at the revelation of Jesus Christ. 14As obedient children, do not conform to the passions of your former ignorance. 15But just as He who called you is holy, so be holy in all you do, 16for it is written: “Be holy, because I am holy.”
Peter deepens the exhortation by reminding believers that the Father they call upon judges impartially, so their exile should be marked by reverent fear. That fear is not servile dread but redeemed seriousness, because they know they were not bought out of their futile inherited way of life with silver or gold. They were redeemed with something infinitely more precious: the blood of Christ, the spotless and blemish-free Lamb. The paragraph binds holy conduct to the costliness of redemption.
17Since you call on a Father who judges each one’s work impartially, conduct yourselves in reverent fear during your stay as foreigners. 18For you know that it was not with perishable things such as silver or gold that you were redeemed from the empty way of life you inherited from your forefathers, 19but with the precious blood of Christ, a lamb without blemish or spot.
Peter closes the section by lifting the readers' eyes to the eternal scope of Christ's work. Christ was foreknown before the foundation of the world and has now been revealed in these last times for their sake. Through Him they believe in the God who raised and glorified Him, so that their faith and hope rest securely in God. The paragraph finishes the call to holiness by rooting it in the eternal plan and resurrection vindication of Christ.
20He was known before the foundation of the world, but was revealed in the last times for your sake. 21Through Him you believe in God, who raised Him from the dead and glorified Him; and so your faith and hope are in God.