A common tactic that I have seen religionists use is the claim that Atheism is Nihilistic. The basic premise is that living this life with no purpose just to have it end is a waste and that simply hoping for more gives meaning and purpose. I reject that argument and propose that living life for a deity, especially if one does not exist could be made into a cartoon and substituted for the definition of Nihilism.
I ran across a quote today that got me thinking about this. "Isn't it enough that you are the Universe experiencing itself." (potentially a quote from Alan Watts if not adopted by Bill Hicks) Science states quite emphatically that the heavy elements on this Earth were created at the centers of high mass stars that exploded. Both Krauss and deGrasse Tyson explain this eloquently and most of us have seen the quotes, so I'll leave those dead horse links out of the post. So we are demonstrably from the universe, living in it, and will return to it ostensibly to aid another creature in experiencing their version of life if not hundreds or millions of creatures over time in whatever form the compounds in out bodies end up taking. I find that to be a warm thought. It's my turn to enjoy sentient life today, and the chemicals and compounds that make that possible today may have the opportunity to live off of my compounds later. You couldn't form a more altruistic existence if you wanted to. Certainly the Abrahamic religions don't as the premise is we have dominion over everything, and God has dominion over us. Rape and pillage all you want for this world will be destroyed anyways. We see this played out in those that deny global warming for religious reasons.
I submit that even on the nicer side of viewing Abrahamic religions, we are still faced with nihilism. The premise that we live in this world for no purpose is in no way changed by the idea of living forever. If you find no meaning in helping your neighbor today, why would you for eternity? But then again, you wouldn't even have to help your neighbor in Heaven, so really, what is the purpose? To exist? I can't think of a more selfish (ahem... nihilist) and purposeless existence.
If one is religious, they must strive to curtail their natural desires (some even avoiding coffee and alcohol... talk about a waste of life) to please a god whom will take them in and keep them under his thumb and rules for all of time as Jesus warns us that none of the laws will ever pass. (Matt 5:18) You are given this life and instructed to not be whom you are or enjoy the fruits on the planet. Then you are going to spend eternity hoping to not piss off this god, not needing to help anyone, not needing to produce anything, without the need to study anything, or to compete in anything because you will all have equal heavenly bodies and we couldn't have someone lose anyways, and this is where you find meaning?
I openly ask the question of religionists. Where is the meaning in just making it to the next world ostensibly to live the same as today just in a different location? I know that Muslims look forward to living freely in the next life which would beg the question about the waste of their lives today if they are wrong. Pascal's Wager indeed. I can only imagine that silently Christians feel the same. Religion makes you feel shame just for being from infancy. I can't tell you how many times religion has been attempted to be sold to me by fear of Hell, and this is where you find meaning? Why not enjoy the world that you have rather than spend 80 years hoping that you are right? A hope based in fear and nihilism. If you think that I'm simply being cynical in my characterization of your religion being fear based, I present to you the Duomo in Florence.
Living life as an Atheist allows me to enjoy the world given to me by a unknown deity or more likely by natural occurrences. At the end of my life I will be happy for having had the opportunity to live it. I will have done my part to make it better not for the selfish purpose of pleasing any other being with power over me, but rather simply because it's the right thing to do. If you live your life in a good way simply for gain, you are anything but good at heart. Being truly moral is taking care of others simply because you can. If you find this to be moral nihilism and a waste of life, you are likely a terrible person and not one that should not be followed by anyone... even if your name is Yaweh.