There is something about the "I don't believe in God" definition of atheist that bothers me. Now maybe I am being too pedantic but doesn't that definition in some way implies there IS a God and I am just not believeing in it and that I am being stubborn?
I usually tell people I am an atheist because I believe there is NO God. I say as a skeptic and rational thinker, although I cannot say categorically that there actually is 100% NO God (as you can never prove the non-existance of something so it's maybe 99.99% :) ), but there is such overwhelming evidence in favour of the No God hypothesis that for me thats the correct and only point of view. I then explain Ockhams Razor.
Any unexplained phenomina that may suggest a God are just that, unexplained. I am comfortable with 'unexplained' and I don't need to fill the gap with God.
People say, "you have faith that science will fill those Gaps" and they "have faith that God did it so we are the same". I say no, the only similarity is the use of the word 'Faith' but the connotation in each instance is very different. They have faith in the literal sense of the word but for me it is not blind, unquestioning faith, but it is confidence. Cofindence based on actual evidence, past histories and success of science and human endevor and confidence in the scientists and philosophers to be able uncover the mysteries behind the gaps.
I am confident they will do it, and I am confident that they will not find God there.