The Greek philosopher Epicurus thought that we are afraid of death mainly because we fail to really grasp nonexistence. Creatures of consciousness, we can only picture it as "me-floating-in-darkness-forever." Is it really suprising that that horrific idea sends people racing to the kneelers to pray to someone who is said to have conquered it for us? Heck, if the darkness was really the thing, I'd be wearing out my own knees. But it isn't. The key, Epicurus says, is to really get that death is the "end" of experience. One can only experience life, up until its final moment, not beyond. "As long as i exist, " he said, "death does not. Once death exists, I will not. Why should i fear something i will never experience?"
He also offered the "symmetry argument." If you fear death, he said, consider the expanse of time before you were conceived. The "past infinity" of nonexistence before your conception is just the same as the "future infinity" of nonexistence after death. "You" have already been there, in other words.
(An excerpt from Parenting Beyond Belief-On Raising Ethical and Caring Kids Without Religion)