Is it possible for an atheist to be moral? This question is one that hasn't been hit (although it's been approached).

Is it possible for a person to not believe in God but live according to a moral standard?  Or is belief in God a prerequisite for morality?



Morality, defined
In order to help refine this question a bit, we'll have to define morality as the parts of the Bible that tell us what is "right" or "wrong", excluding the parts that talk about how we should worship God.  (I know that practically invalidates the Bible, Christianity, and almost all doctrines on morality, but I can't think of a better way to make sense of this.)



I want to point out that I am seeking a Christian perspective on this.  This does refine the question to deal with morality of the Bible more so than the broader definition of morality.
If it is impossible for Atheists to be moral because they don't acknowledge the same source of morality that Christians recognize, then I would argue that it is also impossible for Christians to be moral, because neither do they fully understand the source of morality that they claim to attempt to adhere to.  And without full understanding, it is impossible to fully acknowledge the source of the morality.

Perhaps Christians can be "more" moral than Atheists (since they have a greater understanding of the source of morality), but since the question is asked in binary terms, I believe the binary answer is the same for both groups.

If on the other hand, morality is simply acting in accordance to a moral code, then it is certainly possible, if only in isolated incidents, for either Atheists or Christians to behave according to any given moral code.

Anyone is likely to behave according to any "code of conduct" occasionally, even by accident.

So my elevator answer would be: It is just as possible for Atheists to be moral as it is for Christians to be moral.