Once we're dead, we're gone, is my attitude towards things, we just switch off. All of us piss our lives away striving for success and money, shit like that, it means nothing in the end, really, does it? I am an atheist, OP, I don't believe there is a heaven, or a hell.
Although, if there is some sort of afterlife, I have two theories, it is either a limbo, just nothingness, you are just a consciousness floating around in nothing, you are in none existence, for eternity. Alternate idea; You end up where you want to end up, or what your inner self deems as a paradise, perfection. No matter who you are, charity worker, or a rapist, it's six and two threes, society deems rape, murder, etc, as wrong, nature however does not, nature doesn't judge, there is no higher power that decides where you go, you decide where you go.
But I still stick by my once you die, you die, theory, in the first paragraph.