All people who believe in god but are wrong lose their 'right' to self righteousness. all the things that religious people do to hurt the world will no longer be justified and those people will now have to be held accountable. forcing on others to act or not act, to dress or not dress, to speak or not speak, b/c god says so will no longer fly.
All people who do not believe in god and are wrong lose nothing. according to all religions, god is about love and getting into heaven is about living a good life - and god gets to judge what is a good life. so how an atheist lives now while 'wrongly' believing in the absence of god is how that person will be judged by god. very few religions hold that you have to believe and be apart of certain religion in order to get into heaven. those religions i think, that if god did exist, god would just sadly shake his/her head at.
Even though I KNOW we would never find that out (because if society did find that, they would be wrong). Well, I have a lot of incomplete thoughts in my mind right now so.... I'll leave that as an incomplete sentence. Anyway, say we were in some alternate dimension in another universe, and in a dream, we would lose all meaning to our lives and the safe feeling of knowing the answers to the mysteries of the universe, and atheists would only lose the happiness of having happy family members. I hope that this does not sound too one-sided ( :