The Bible says that God lives within all of us. There is no man on Earth who doesn't wonder where they came from, where they are going, and what their purpose is on Earth. Even atheists have this inclination to seek out God through believers and try to tear his existence down. Now people of all faiths and "none" (though to be an atheist IS a faith) do some really messed up things and always have, but it doesn't make their belief in God false.

Also think about this; why do people fear death? Is it because they don't know what happens after death? Uh, no, a straw man argument. People fear the death itself. Death is usually painful, people feel they'd be leaving this world without fulfilling their dreams, it can sneak up on you or anyone you know at any time, and most people just aren't ready to die. Ever.

Believing something happens after death is comforting but certainly not going to sway me into believing God exists because that doesn't solve the problem of me dying, and more than likely, a very painful death.