[Aliantha]

Good question Sam. My thoughts are that we believe or have faith in some God or other simply because we're so narcisitic as a species that we can't imagine only having one life like everything else. We can't accept we're just an organic construct, so we must be special where everything else isn't, so in order to waylay these fears somewhat, we've created higher powers.

Also, not too many people have ever found a good way of explaining death of loved ones to children without including all those lovely fairy stories about heaven and angels.