I know, why waste your precious limited time on Earth if there is nothing after this?
But if there is nothing after this, why not waste your time? After all, if your life has no ultimate meaning it doesn’t really matter what you do with it. So you might as well wallow in self-gratification. Not the best way to build a healthy culture.
Anyway, this is fighting the battle on the Humanists terms. I don’t believe in God because of the promises He has made for me after I die. I believe in God because of the promises He has made for me here and now.