Science is not the search for an explanation of the universe

Science is, in reality, only the pursuit of "sufficient" truth - truth that will explain the entirety of the observable universe. Scientifically, the statements "God made the world through the big bang blah blah blah", "God made the world 6000 years ago to look like it was made through the big bang blah blah blah", and "the big bang happened" are all the same. They will all generate the exact same results in laboratory experiments.

Atheists aren't more scientific then theists. Atheists aren't even the source of scientific knowledge/revolutions - skeptics are. Descartes was able explore geometry, and he wasn't motivated by anything except the search for absolutely true axioms. However, in the universe, there are few absolute explanations. There are only truths of interaction.

Science only seeks to be able to predict - to make hypotheses that can be tested and reproduced. "God made the big bang happen" is not scientific - however, the statement "no god exists" is equally unscientific. Hell, even the statement "the real world exists" is no more scientific than the statement "the real world is a vast illusion played out to me by a tricky demon". Science has no interest in the unprovable. Except through logical contradictions, no conclusion on a god or the lack thereof can be reached (scientifically).

Finally, consider the dreaming skeptic argument. I've had ridiculously real dreams in the past - prove to me that the world I am in now is not a dream. If you find yourself unable, that is because these things cannot be proved. The belief that this world is real is just as much a belief as any other.