Is it true that there is no absolute morality?

[CapnAwesome]

I've seen people say a lot that there is an absolute morality, but it seems to me that there is not. For example, some people say that killing is ultimately wrong, but there can be no reason why one thinks killing is wrong, other than personal desire. Personal desire is not quantifiable, therefor it's an arbitrary measurement of a person's feelings. 

It would seem were it not for this problem, there wouldn't be religion, which tries to solve this problem through dogma, and the imposition of an imaginary creator of whom punishment is inescapable. It would seem to me, that all morality is nothing more than dogmas, whether it be social norms or enforced laws. 

How does one cope with knowing that all morality is arbitrary, and say that one respects morality beyond being blinded by dogmas, or simply appreciating the geometry of such arbitrary systems? on a purely intellectual level. The alternative is, of course, "psychopathy", where the dogmas and appreciation of arbitrary systems is absent.

By cope, I mean cope with the fact that the systems in place are arbitrary, so there's no one system which can ultimately bring about the best of humanity. Without an objective morality, of which one could appeal to every person through reason, there is basically only wars and dogmas that struggle for dominance.

When followed to it's logical conclusion, atheism seems to result in a depressing philosophy - nihilism. I'm going with the God-is-not-dead theme and ground my reality in something objective. 

Most of the famous Atheist philosophers haven't been nihilists. In fact, I don't know that any of them were.