What was the relationship between Rahim and Amir in The Kite Runner, and did Amir prefer Rahim over his Baba?
Amir has a close relationship with his father's best friend and business partner, Rahim Khan. The novel opens with Amir receiving a call from Rahim, who is asking him to come to Pakistan, as he is very ill. He also suggests that this trip is a way for Amir "to be good again," so he is helping Amir atone for some wrongdoing, which we later learn about when Amir narrates his childhood experiences. Rahim Khan is not Amir's father, of course, but he stands in as the kind of father Amir wishes he had; his relationship with his father, Baba, is strained and tense.
Baba is a very powerful, successful man. He expects his son to follow in his footsteps, but Amir is more sensitive and creative than his father. Furthermore, Amir's mother died in childbirth, and Amir thinks Baba's less-than-warm treatment of him may be due to his feeling that Amir is at fault for his mother's / Baba's wife's death. When Amir is a child, Baba confides to Rahim (and Amir overhears) that he worries about Amir because he may not be able to defend himself out in the real world:
"And where is he headed?" Baba said. "A boy who won't stand up for himself becomes a man who can't stand up to anything" (22).
Baba even goes so far as to tell Rahim, "'If I hadn't seen the doctor pull him out of my wife with my own eyes, I'd never believe he's my son'" (23). Rahim is more gentle and understanding of Amir's dreams. Amir wants to be a writer, and Rahim supportively reads Amir's works, while Baba barely glances at the stories. Rahim even gives Amir a writing notebook in which to record his stories. Although Amir appreciates Rahim and their close relationship, he desperately wants Baba's approval. This is why he vows to win the kite fighting competition that leads to all of the tragedy that follows in his life.
Eventually, Amir and Baba flee Afghanistan and move to California. They become closer when living in the United States, and especially once Amir marries Soraya and they all live in the same home. After Baba's death, Amir learns that Baba hid a major secret from him: that Baba was Hassan's father and that Amir and Hassan are half-brothers. The tension between the two continues after Baba's death, though Amir does forgive his father. Meanwhile, it is Rahim who presents this opportunity for Amir to redeem himself by adopting Hassan's son, who is also Amir's nephew.
I don't know that it is fair to say Amir prefers Rahim over Baba, but he certainly has an easier relationship with Rahim. His bond with Baba is undoubtable, but their expectations of one another lead to tension and stress.
Rahim Khan is Amir's confidante, the only adult Amir can turn to when he needs to get something off his chest. Rahim is always supportive of Amir, providing him with the positive reinforcement that he rarely gets from Baba. Rahim convinces Amir to continue writing after Baba "feigned interest" in his son's first short story; it is Rahim who "rescued me" from Baba's long silence and refusal to read even one word of Amir's story. Rahim "buoyed" Amir's spirits by asking to read it and then provided him with a note that assured Amir that
My door is and always will be open to you. (Chapter Four)
Rahim defends Amir when Baba is critical of his son's lack of a "mean streak," and it is from Rahim that Amir learns much of his family's history. Amir still "worshiped Baba," but there were times when
I wished I could open my veins and drain his cursed blood from my body. (Chapter Four)
... Baba's quiet alter ego, my writing mentor, my pal..., (Chapter Eight)
and it is Rahim who convinces Amir to return to Afghanistan, where the boy he never stopped loving could finally find that "There is a way to be good again."
As was mentioned in the previous post, Rahim Khan is Amir's close friend and confidant. Unlike Baba, Rahim Khan understands Amir and offers him encouragement after reading his first story. Rahim Khan supports Amir's dream of becoming an author and even buys him a leather notebook for his birthday so that he can write his stories inside. Although Amir loves his father, he wishes that Baba would treat him like Rahim Khan treats him. Rahim Khan makes Amir feel special and worthy, which is why he prefers Rahim over his father at times. Rahim Khan also understands Amir's secret and provides him a chance "to be good again" by asking him to save Sohrab from a dangerous life in Kabul. Rahim Khan even tells Amir the truth about his upbringing and family. Amir is shocked to learn from Rahim Khan that Hassan is actually his brother. Rahim Khan then provides Amir an opportunity to redeem himself by sharing Sohrab's story with him. Throughout the novel, Rahim Khan offers his support, advice, and friendship to Amir.