I think at its base, morality is biological.  After all if members of a species kill each other off, the odds of that species lasting for a significant amount of time is low, so in my opinion, many "moral" behaviors are more rightly called "biologic" or "evolutionarily advantageous" behaviors and are ingrained into our DNA.  Just today I saw a video of a monkey (I'm not sure what kind), essentially saving the life of another monkey that had been electrocuted.  I'm pretty certain that the monkey providing first aid has never been to church, nor read the bible.  It was simply doing what gives it's species the best chance to continue to exist. 

Personally, my approach to morality is to not do to others what I don't want done to me.   I prefer to continue to live, so I don't kill other people (or if I can help it, animals for that matter.....weeds and mosquitoes, though are firmly in my cross hairs).  I would feel horrible if my wife cheated on me sexually, so I don't do that either.  It pisses me off when people steal from me....so I don't do that, and the list goes on.  My behavior has absolutely nothing to do with proclamations or admonitions from some ill tempered spirit.

- Sam Ogden