Khaled Hosseini's celebrated novel The Kite Runner is considered a heart-wrenching redemption story that chronicles Amir's journey to seek redemption and atone for his past sins. As a child, Amir witnesses his best friend, Hassan, being raped by a bully named Assef, and Amir refuses to intervene. Following the traumatic incident, Amir becomes overwhelmed with guilt and his relationship with Hassan is permanently ruined.
Amir's guilt follows him into adulthood, and he spends the majority of his life suppressing his past transgressions. One day, Amir receives a phone call from Rahim Khan, who tells him that there is a way to be good again. Amir ends up traveling to Pakistan, where Rahim informs him that Hassan was his illegitimate half-brother. Rahim also explains that Hassan's son, Sohrab, is currently living in Kabul, which is currently occupied by Taliban forces.
Amir decides to seek redemption and atone for his past sins by rescuing Sohrab from a life of abuse and suffering. Amir travels to Kabul, where he locates Sohrab and is forced to fight Assef in hand-to-hand combat to rescue Hassan's son. Fortunately, Sohrab helps Amir defeat Assef, and they narrowly escape Kabul.
While Amir is in the hospital, he reads Rahim's letter, which says that true redemption is when "guilt leads to good." Rahim's comment accurately defines the concept of redemption, which is essentially clearing one's debt and making up for past transgressions. By engaging in a positive act, one is able to erase their prior transgression and atone for their sins, which is exactly what Amir does.
Given the extent of Amir's past transgression, he must sacrifice his life and well-being to atone for his sins. For Amir to fully experience redemption, he must engage in a selfless act and risk everything to save Sohrab. Amir's conscience and Rahim Khan's encouragement motivates him to rescue and adopt Sohrab. Once Amir successfully adopts Sohrab, the weight of his sins is lifted, and he begins the emotional healing process.