From what I understand, it relates to the simple idea that being a moral person and leading a moral life is much more satisfying to ones self and to humanity, than being an immoral jerk. Do you really believe that without God guiding the way, all people are intrinsically evil or immoral? How would that explain all the immoral yet religious people I know? If you're a Christian, assuming you are from your original post, I would think you'd know better.
I kinda think Jesus wouldn't care for atheists too much. Wasn't much tolerance for much back then.
Personally, that is between them and their