How Can Atheists Be Moral?

Q: What is your motivation to live a moral, upstanding life without the guidance of the rules of God and the Bible? I know you guys do this, but I'm not sure I understand how it works without concrete guidance.

A: "I live a moral life for the simple reason that I empathize with my fellow human beings and have a desire to avoid doing them harm that's almost as strong as my desire that they avoid harming me" ~PZ Myers

That pretty much sums it up for me.  That, and the fact that the rules of so-called God and the Bible are pretty horrific, if you actually bother to read them.  Frankly, I'm not sure how anyone *can* live a moral life WITH the guidance of those rules.  Stoning women, killing children for the sins of their parents, sending daughters out to be raped ... there are some passages about love thy neighbor in the bible, but there are a lot of passages about killing thy neighbor too, and I don't see how anyone can justify the cognitive dissonance of "morality" found within the pages of the bible.  I find it a lot easier to be "moral" without that sort of concrete guidance, personally.  

I like my morality the way I like my entertainment - internally consistent and logically plausible.