Why 'should' atheists be moral?

[robvalue]

Thank you I added a bit more to my post to address the hypocrisy of religious morality.

Yes, I think a society as a whole can come to a decent agreement about what is and isn't moral as people tend to find many of the same things helpful or harmful. An individual may agree with a particular moral of the society, say not stealing, and think it is wrong to steal, but do it anyway because they weigh their benefit as more important to them than the morality. They may know it is wrong, and may well feel bad, but have given in to selfish desires.

An individual making a decision is a very complex process and morality is one of but not the only factor.

In a way, the thief has performed a kind of morality check. He has determined the benefit of him having the thing he stole outweighs, in his opinion, the harm he knows he has done. He may later re-evaluate this analysis and decide in fact he had it wrong, and feel vey guilty. Different morals will often be in conflict, so we live life in a grey area. For example, the thief may be stealing bread because he is starving. He may then view the wrongness of theft to be less than stealing for the sake of it.

If religious people are argueing about morals, another good thing is to point out that a black and white view of morlality is next to useless. The harm and benefit of each action varies greatly with context, and you often have to choose between two harmful actions. A checklist does not help you here.