I think the idea that we will all die one day makes life seem so much more valuable and precious. I feel that the belief that there is an afterlife can potentially lead to more complacency and wastage of time in this life and prevent us from making the very most of the time that we have. Sure, I don't want to die, but how miraculously lucky are we all to have woken up into this world and so, as a result, I don't believe we have the right complain about the fact that it will end.
"The chances of each of us coming into existence are infinitesimally small, and even though we shall all die some day, we should count ourselves fantastically lucky to get our decades in the sun." - Richard Dawkins