This is a complicated answer for me. I know that god isn't floating around in space somewhere, but I still like to believe he is there because it does give me hope. A lot of atheists I know personally are also kind of dick heads, like just fucking scum of the earth douche bags. Besides it is also encouraging to think that I will be taken care of when I die, even though I will just get burnt up in an oven. It is just a reassuring fact. I don't go to church, because I think that if god was loving and forgiving you wouldn't have to go...I also have never read the entire bible. I would just prefer to have a reassuring fact, rather than just bashing on people for believing in god....since thats what most atheists I know do.
Meh.
Asshole atheists are annoying, I give you that.
Some of us though, just find it frustrating. Many of us have forgotten how we've came to the conclusions we have, and many years later, think it all just makes sense. We forget it wasn't really a revelation in our minds, it was a slow building momentum.. the quick moment was the "aha! woah, well I guess I actually don't believe any of this" that we think of as the change in heart.
Ultimately, many of us, even if we approach it wrong at times, are really putting our heart into the issue. The whole notion of Enlightenment, be it religious, or based around philosophical, sociological or psychological concepts, is to soak up knowledge and go out with that knowledge, to enlighten as many people as one can. It's not about "spreading belief", though I admit it is quite similar... rather, we think there are serious potential problems that may occur if people don't learn certain things now, so we try and hasten the learning process... instead of mankind's old standby - learn when it's practically too late, where the losses are extreme, and your collective group is no longer guaranteed to continue existing into the next decade, let alone century or millennium.
Some may disagree with the basic ideas at the heart of the matter, but we really are just trying to make the world a better place.

It's simply through the
removal of belief systems, and not an attempt to get all of mankind to unite under a common belief system.
Eventually, some Atheists get bitter at being ignored/shunned for so long, or worse, told they are sinful bastards who will die a thousand deaths or some such nonsense.
As far as rewards for being a good person, and carrots at the end of the stick - regardless of what might actually be the reality of afterlifes, I think it's time we move on. Reward at the end, with no expectation? Woah, sweet! But for me, simply being given this time to try and make my species better, to enjoy life, I'm quite content. Could I be doing better? Hell yes - but it could be a lot worse. And the sad fact is, it's a lot worse for billions of our own species. Am I proposing we swoop in to save them? No, because in some ways, we should envy them. But my idea of enlightenment would help unite the world under a single banner, where we all share the same pains and same glory, where we fight for research grants, in boardrooms, in classrooms, for the chance to be apart of the next revolutionary advancement... not for blood over rights of imaginary boundaries.
And most certainly a global republic, not some imaginary communist dream of perfect peace. But all of our heads together on the same exact problems, cooperating instead of working individually to reach the same goals? Everything takes longer the way we are doing things at the moment. If we're to survive extinction at the hands of nature or an invading alien army, we seriously have to stop putting off future crisis for future generations, if there's any chance we can hasten the new age anytime soon.