I think we need to make a distinction between a Supreme Being and an Omnipotent, Infinite Force. Religion, which is an invention of man, has crafted "god" in the image of a person, making "him" either a petty, vindictive old man who doles out punishment, or a Mystical prophet who spouts riddles. And any one who judges people by the bible or other religious scriptures written by men is not qualified to be objectve. To say that an atheist can't be "moral" is simply an opinion.
In the big picture, there is no such thing as good or evil or moral or immoral or Satan or God. There is simply matter and anti-matter, negative and positive, darkness and light. The "good" and "bad" labels are constructs of civilization. But, as is proven everyday, these opposing energies co-exist.
And any scientist who cannot explain what came before the Big Bang, or what caused the spontaneous combustion that ignited it, needs to expand his vocabulary. The word "nothing" is inadequate.