When they had finished breakfast, Jesus said to Simon Peter, "Simon, son of John, do you love me more than these?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Feed my lambs." A second time he said to him, "Simon, son of John, do you love me?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Tend my sheep." He said to him the third time, "Simon, son of John, do you love me?" Peter was grieved because he said to him the third time, "Do you love me?" And he said to him, "Lord, you know everything; you know that I love you." Jesus said to him, "Feed my sheep." John 21:7, 14-17 (RSV)
Because he knew the reality of his sin and failure, Peter ran to Christ rather than away from him. When God called to Adam in the garden, asking, "Adam, where art thou?" (Gen.3:9) he showed that his intention was to restore sinners by his grace to his favor as elect and beloved. For this reason Christ died, and to justify us he rose again (Rom.4:25). He stood on the shore and welcomed the approach of not only Peter, but of all of these men who had forsaken him and fled; for only John had come to the foot of the cross.
Why did Jesus give Peter three opportunities to speak of his love? What was this love of Peter's now but a sincere intention to love? Unable to rise to the highest love (ἀγαπάω) by human strength, Peter was humble enough to answer in terms of his intention to be a friend (φιλέω) of God; and Jesus met him at that point of sincere intention. Jesus gave Peter these three opportunities because he had denied the Lord exactly that many times, three times before the cock crowed on that Friday morning. This was not necessary for Peter to be forgiven; rather, it was a necessary aid to Peter for what would lie ahead.
Penance is not atonement; the only atonement for our sins was accomplished when Christ paid in full for our sins (John 20:30 τελέω). Penance does not earn forgiveness; in fact, it is done after Absolution has been given, never before. This story as John tells it, where Jesus gives Peter three opportunities to speak of his love, however imperfect that love may have been, teaches us what penance is about. It redirects the soul to God, indeed, the redeemed and forgiven soul.
Forgiveness is about the past. Penance is about the future. In penance we say to Jesus, "Lord you know everything; You know I love you." So, Jesus, who formerly said to us "when thou art converted, strengthen thy brethren," (Luke22:32) now says to us, "feed my sheep." He knew we would fail; he knew we would be converted. After forgiveness, after we are converted and restored, he gives us penance to redirect our souls in love and worship as holy, elect and beloved of the Father. Then he calls us, everyone of us, to a life of service.
How sad that this wonderful gift of penance has been twisted into an attempt to do the impossible, that is to atone. How sad that it is often mistaken as some price we pay for sin, as if we could pay such a price with anything less than an eternity in Hell (which is not the will of God at all). "Say three Our Fathers and two Hail Marys." I have required this as penance: "I will leave you here alone before the altar; read-rather pray-the words of Psalm 51." I have seen a grown man come to me afterward with tears in his eyes, happy tears because he learned there and then that Jesus loved him, as if he had only now learned it for the first time. "Now you know the love of Christ for you," I said.
This is what penance is, and what it is for: It meets our need to say, "Lord you know everything; You know I love you"