Long ago, the failed presidential candidate, Ross Perot, said that he could not understand how anyone felt they could trust someone who didn't believe in God (his, of course) because, without a divine imperative, why would they adhere to any moral code. That pissed me off and I've been thinking about it ever since.
The essay above is the basic idea of my answer to the question, Where does morality come from if humans are basically just overgrown yeast cells in a universe that doesn't care. Or, more simply, why don't we kill each other with the same zest as great white sharks at a beach.
The basic premise is that our brains are built to appreciate order and safety. Other things, too, that add up to what the religious types attribute to "God's will" but are instead fundamental aspects of human biology.
Along the way, I have become interested in philosophy. It turns out that there are a lot of people who have tried to figure out more about what is going on in our culture and the universe. Among those are the two I mention above, Kierkegaard and Sartre (he's the guy that inspired the picture below). They are among the earliest people (along with Hume and Kant a hundred years before from a completely different perspective) to really explore how humans get their morality without assuming 'God made them do it'.
Neurological Existentialism is an attempt to improve on their answers. On the one hand by explaining how we could be 'good' without God to tell us how. On the other, how we can be fulfilled without God telling us that we are ok.