>>75
To satisfy our curiosity, and to increase our odds of perpetuating the species are two reasons I can think of.
But if you're a theist who intends to play the "Why? Why? Why?" game, I would ask you, "Why bother even if there *is* a god and an afterlife? To worship this god? What for? Because he said so? So what?" Eventually you'll come to a point where you'll say, "Well, that's good enough for me." And, well, satisfying my curiosity and increasing the odds of perpetuating the species are good enough for me. :)