What does the man see in his boy?

Certainly the boy radiates empathy. The boy seems to hold the last vestiges of humanity left in this fallen world; the boy is hope. Indeed the father says in his narrative that, "All I know is the child is my warrant, and if he is not the word of God, then God never spoke." I wouldn't go as far as to say the boy is God but he seems to be a Christ-figure. In a world that has become Hell, the boy reaches out to striangers that might harm him. He truly personifies hope on a damned planet.