What is the theme in The Road by Cormac McCarthy?

There are so many themes in this book. I think one of the larger themes is simply death. The planet is on its last gasps of breath, humanity is dead, the animals are dead.....Death and the specter that haunts the narrative at every turn. Death is darkness but the boy is a small light that shines through. He is the Biblical light that does not fade: he is the light that rebukes complete darkness and human appocolypse.