From Unbecoming Levity, incidentally one of the most recent members of Planet Atheism, comes a brilliant — and beautiful — post, Why I am an atheist.
As deconversion stories go, this is one of the most enlightening I’ve seen, and, while the specifics are different, some parts almost echo my own experience. The following, for instance, could apply perfectly to me:
It became clear that God is a product of man, and he still exists as a go-to for those questions that still are not answered and to comfort us. Through a god and afterlife, we are eternal, our consciousness the manifestation of an immortal spirit that will rejoin its loved ones who have passed on before when we die. The God hypothesis makes us live forever. And further, it addresses the common lament that life is not fair, God will mete out justice. If an awful, evil man becomes powerful and lives a long happy life hurting others, we can take solace that after death, he will be brought to account for his transgressions. The God hypothesis makes life fair. This is why the God hypothesis exists–to make us feel better. It is a comforting idea, in my opinion. But that doesn’t make it true.
Really, go read it. You won’t regret it. And send the link to any theist (but inquiring) friends you happen to have. 
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it was an ingenious blog post.
…how i became an atheist? i read your blog.