If you've got some time, I recommend perusing The Lens, a blog by my twitter friend Ali. Ali, a former Muslim, lends an interesting perspective on the intersection of religion and culture that I and many former Christians have likely never seen.
From what I've seen, Islam seems to be more deeply embedded in the culture of its followers than the beliefs of most Christians are embedded in theirs. This is something I'm only just coming to recognize, but it's an important point. When I tell people I'm an atheist, they tend to get a little freaked out by it, but it doesn't shake their world off of its foundations. When an ex-Muslim tells other Muslims that they're an atheist, it's not so simple. The Godless Monster related it this way over on Hemant Mehta's blog:
I get sick and tired of running into other Arabs and have them ask me if I am Muslim and then hear them respond to my declaration of non-belief by saying, “No!!! Once a Muslim, always a Muslim! You can NEVER go back! Never say that!”I agree, and the more horror stories I read from former Muslims, the more I realize how smoothly my 'coming out' has gone.
I had to fake I was a believer at a cousin’s funeral when I was in southern Lebanon last month. How humiliating. It just wears you down emotionally after awhile. The entire culture and religion is obsessed with compliance and subordination and woe be to those who rock the boat or betray their own kind as I have. You former Christians and Jews have no idea how lucky you are.