TG: This topic has been done a thousand times before, beaten to death and back enough times that it hardly even makes a difference, ****ed sideways, and sent to the Moon. It's tired and old, and it's been done to death on this forum, too.
Ruling out the concept of god does not equal ruling out the fact that we need a social construct with limitations, and in fact personal guidelines and restrictions, in order to remain sane, healthy, and alive. It has absolutely nothing to do with God- morals and law never did. Religion coopted them, not the other way around.
In fact, it's been said before that atheists are the only truly moral people around- the fact that all y'all have that big fat ol' carrot of an eternity in Heaven if you're good dangling in front of your noses pretty much negates altruism, since it's all in self-interest in the end- you do it because it gets you in God's nice list (or at least not on the naughty list), not because it's good for anyone else. However, an atheist doesn't have that, and not all moral restrictions have to do with self-preservation- hence, it basically comes down to atheists, and atheists alone, being capable of being good for the sake of good.
Ahh, being smug. It's so rewarding.