What is the symbolism of death as the omniscient numerator of the novel?

Death ironically represents a sense of innocence. A metaphysical being, Death serves as the dryly cynical narrator of The Book Thief who is discovering the depths and deprivations of human nature. Death's duty is to carry away the souls of the recently departed, which it has apparently done for millenia. In its line of work, Death tries to focus on colors as a way of distracting itself from the survivors of those who have died. Liesel's story is one of a handful of survivors' tales that Death remembers; in fact, Death retrieves the actual written autobiography of Liesel's life after the air raid at the end of the novel. Death is "haunted" by humans and unable to reconcile humanity's capacity for evil with humanity's capacity for good.