I don't really think about it one way or the other, whether my atheism is active or passive. Nor am I concerned with how people want to define it. I make it pretty simple: I can't prove god does not exist, and until someone can get god to show up, I will continue to believe that he does not. There are a great many things that we believe don't exist, many of which we cannot prove. There have likely been many more things which people didn't believe in until they were proven. Prove god and we can add her to the list. Until then, she stays on the shelf next to unicorns and mermaids.
"Well, evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts don't go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's in this century, but apples didn't suspend themselves in midair, pending the outcome. And humans evolved from ape- like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered."
-Stephen Jay Gould
-Stephen Jay Gould