I am late to this forum, obviously. Like Stopper, I became an atheist rather early. Sunday school (I went twice) was unconvincing. I now write on atheist issues.
One thing, though that I feel strongly is that atheists should get into the debate on the nature of morality n order to remove the religious vocabulary that surrounds it. "Good" and "evil" are real enough, but what are they? How can we discuss them without resorting to concepts that are more spiritual than concrete. For that matter, can we talk about matters of the spirit (the mind, the "soul", if you will) in a way that in anchored to the real world?
The approach (let's not talk of answers too glibly) is to derive moral concepts from nature and human behavior. As a lawyer with a degree in economics, I sort of do this naturally (too jaded to do otherwise, I guess). But I do find that it is possible to avoid the trap of "moral relativism," that epithet that religious types throw at atheist so often. But this is not to say that morality is absolute, either. Morality is based on survival. Faith, to my mind, is the trust that grows among people so that we are not only creatures of the jungle, fighting and killing constantly (though we sink to his pattern often enough). It is this faith/trust that is the kernel of moral behavior.
Interestingly, I find that the concept of a monotheistic God is totally dependent on this natural morality existing first, because we cannot have faith in a god without having faith in each other. Pagan deities were not trusted in the same way. their realm was above and apart and their interference in human affairs was capricious, like the forces of nature, not the result of any possessive "jealousy," as the Hebrew god behaved. 
Well TPN I'm incline myself to believe that the Greeks, in their religion, as in most things, had it right. The pagan gods were of course of nature and the seasons but in the delightful writings of the great Greek poets and playwrights there was laid out a family of humans with all of their doubts, worries, fears and jealousies writ large on Mount Olympus. These humans had the powers of Gods though, and the playwrights showed that the giving of too much power to any human was not recommended. An education that we have most definitely forgotten.
The accumulation of powers was the result of the monotheistic God and this gave such accumulations legitimation, which was the whole point in my opinion, the one God was meant to vanquish the many, this is the arch head of our hierarchic system, that takes from the many and gives to the few.