Existence of a "god" or not is not part of a religious discussion IMO.
In religion there is "one god" and if you believe in another "god" or if you have absence of belief, you are going to suffer.
Now, when you talk about atheists, you talk about the internet trolls that think they have absence of belief but they are just angry at(their own opinion of what is) god, right?
Because an actual atheist doesn't believe in what religions consider god. This doesn't mean that atheists don't believe in anything greater than us. For example nature is greater than us, we are part of nature, not nature itself.
About god, I have no belief in a god. Everything is what everything is, actions and reactions controled by no god but the actions and recations themselves. Although, I can't say I wouldn't be fancinated if we figure out that everything, included us was created by an inteligent species.
About an afterlife, fuck i don't know