I believed beyond any doubt when I was a theist. I had been told that these things existed, and everyone around us pretended that it did. I can recall many stories and accounts of people who had witnessed the supernatural (though I cannot recall any first-person accounts) which strengthened the belief in such things. When you take a core belief (eg: god exists, and it is this particular god) for granted, you work very hard to make everything you know and experience fit that belief, and then you sincerely believe that they support the belief instead of the other way around. It is a self-reinforcing loop. Until you challenge that deeply-held belief, everything else must fall into place around it. The mind will not allow otherwise, IMO.
"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
