The thief, Hari Singh, became a friend to Anil primarily because of Anil's unwavering trust, kindness, and forgiving nature. Anil not only gave him a place to stay and work but also began teaching him how to read, write, and cook, offering him a path to a respectable life. Even after Hari stole his money, Anil’s unspoken forgiveness upon his return had a profound transformative effect on him. This kindness and the opportunity for education made Hari Singh value their relationship over the stolen money, leading to a genuine change of heart and friendship.