I didn't choose to stop believing in God. To the contrary, my epiphany was the realization that I couldn't simply choose what I did and didn't want to believe. Belief needs to be based on evidence. What's true is what's true; my personal desire is irrelevant. Or to put it more crudely: the universe doesn't give a shit what I think.
I remain agnostic on the question of whether or not some form of divine being exists. If so, it clearly isn't the insecure narcissistic sadist I used to worship. The Christian god is a product of a long distant time. While He's still popular, belief in Him requires a willful suspension of disbelief. There's too much about the Bible and Christianity that don't make any sense to an objective observer.
Of course, the Christian answer to any objection is to simply "have faith". In recent years attempts have been made to provide more concrete arguments justifying that faith; witness the farce of Intelligent Design. But ultimately, their defense of their belief system will fall back on declaring that they believe what they want to believe. The fact that there is absolutely no supporting evidence for their position is turned into a positive.
If it seems like I'm picking on Christians, consider that I'm an ex-Christian living in the Bible belt. They're the religious group I'm most familiar with and the only one I regularly come into contact with. Pretty much every other organised religious group in the world suffers from the same flaw of relying on claiming faith when reality collides with their religious doctrine.
The problem I have is with faith, not religion as such. Don't get me wrong, I think spirituality is a good thing. I only have a problem when faith is used to ignore reality. There's more than enough in the natural world to inspire awe; there's no need to invent a supernatural one. Take strength from what is real, don't rely on self-delusion.