Rahim Khan, who can be characterized as a wise man, is the person who truly understands how redemption occurs. He tells Amir in his letter, "I know that in the end, God will forgive. He will forgive your father, me, and you too ... Forgive your father if you can. Forgive me if you wish. But most important, forgive yourself."(Hosseini 302).
Rahim Khan carries the novel's main message about forgiveness: it is that God is merciful, and it is people who are not.
Therefore, truly atoning for one's sins means coming to terms with them by oneself, without relying on a higher power.
When Amir manages to forgive himself in the end of the novel, he redeems himself at last and giving Sohrab an equal chance of happyness
When Amir prays, he is bound by fear and guilt. However, instead of wishing unselfishly for Sohrab to recover, he begs God not to leave "Sohrab's blood on his hands."