I think people misunderstand atheism. Here's an explanation for what I believe, how I believe it, and why (obviously, not my own words):

"Really religious difficulties, for example, I don't know from experience. It has escaped me altogether in what way I was supposed to be "sinful". Likewise, I lack any reliable criterion for recognizing the bit of conscience: according to what one hears about it, the bite of conscience does not seem respectable to me.

[...]

"God," "immortality of the soul," "redemption," "beyond" -- without exception, concepts to which I never devoted any attention, or time; not even as a child. Perhaps I have never been childlike enough for them?

"I do not mean I know atheim as a result; even less as an event: it is a matter of course with me, from instinct. I am too inquisitive, too questiopnable, too exuberant to stand for any gross answer. God is a gross answer, an indelicacy against us thinkers -- at bottom merely a gross prohibition for us: you shall not think!"

-Nietzsche, Ecce Homo, "Why I am so clever" (yup, that's the title of the chapter )