This question has previously been answered fully and is linked below. A couple of motifs are: Pashtans and Hazaras’ friendship. This is developed throughout the early part of the book. The are from two very different cultures, religions, and social status yet they remain friends.
Another motif is that of Amir's dad Baba. Baba is the courageous one. The moral compass in the story. Baba always does what is right. His model as a man and a courageous person finally rub off on his son.