is Rhim Khan correct when he says, "true redemption is... when guilt leads to good?"

Khaled Hosseini's The Kite Runner begins with the novel's protagonist, Amir, receiving a call from his past. His late father's dear friend, Rahim Khan, requests that Amir travel to see him in Pakistan. Knowing that Amir will be hesitant to do so for a plethora of reasons, Rahim Khan tells him, "There is a way to be good again." He seemingly knows Amir better than any other person, even more so than Amir's wife, and he recognizes that Amir will never have peace in his life or find true redemption until he acknowledges what he did all those years ago in Afghanistan and takes action to do good—Amir can never make up for what he did (or didn't do), but Rahim Khan eventually tells Amir that he has an opportunity to save the son of the dear friend that Amir so despicably betrayed. Amir, who has lived a tortured life because of his actions as a young boy, does follow Rahim Khan's advice and in his own way feels redeemed after he has saved Hassan's son.
In regards to Rahim Khan's philosophy, its truth is relevant to one's perspective on redemption, but many would see the truth in his statement. While The Kite Runner is fictional, we see articles or news clips about people who have recklessly caused the death of a friend or someone else who redeem themselves not by simply apologizing to the family members of the deceased but in many cases becoming advocates who speak out against the type of behavior they once exhibited. This is a much more meaningful way to deal with one's "sins" than merely feeling guilty about them or only apologizing for them.
https://www.cosmopolitan.com/lifestyle/a50255/three-people-killed-drunk-driving-story/