A pair of lines from Augustus Toplady’s eighteenth-century hymn “Rock of Ages” address what Christ’s atonement brings about in the Christian’s life: “Be of sin the double cure, Save me from its guilt and power.” A look at the life and teaching of another rock, the Apostle Peter (Petros means “rock”), will provide insight into the meaning of these poignant lines.

Peter the Man

The picture we have of Peter in the Gospels is of a disciple who had trouble getting out of his own way. He was at turns brashly presumptuous (Matt. 16:22; 17:3–4; Mark 14:29) and zealous for the Lord’s honor (Luke 22:49–50). At his worst, he was a denier of Christ (John 18:15–18, 25–27).

Between the Gospels and his epistles, there is a change. After Peter was restored in John 21:15–19, he burst on the scene of the early church giving bold witness to Christ. What is more, in his letters, he is no longer the fumbling Apostle—he’s a mature believer calling other believers to maturity.

What power worked in his life effecting such a change? Of course, we can point to the Holy Spirit sowing seeds that produce increasingly visible fruit in Peter’s personality. But there is an objective touchstone to which we can point, to which Peter himself pointed: the blood of Christ.

Peter’s Message

As Peter opens his first letter, he addresses a diverse group of Christians dispersed throughout Asia Minor (modern-day Turkey) and celebrates the triune God’s work in their lives: the Father foreknew them, the Spirit sanctifies them, and Jesus Christ sprinkled them with His blood (1:3).

The language of sprinkling recalls Old Testament images that tied blood to the forgiveness of sin. Three of these passages will help us understand Peter’s message about the blood of Christ’s crucifixion.