I found this study on atheists and agnostics and thought some of you might be interested:
Atheists, Agnostics, and AA. You must pay for the article in order to read the entire thing, but the conclusions are free and available on several sites, including this one:
Results of Study.
In a nutshell, it appears that a belief in God has little or no effect on length of sobriety, but attending 12 step meetings seems to help. The most glaring problem seems to be that those who are atheist/agnostic are less likely to continue attending meetings, for obvious reasons (obvious to me anyway). The group in the most trouble is those who are "undecided"--meaning they don't know if they're agnostic, atheist, spiritual or what. They had the highest rates of relapse and drank the most. I guess there's some merit when they say, "God is everything or nothing." Nothing is okay, but "I don't know" may get you into trouble. For myself, I attend meetings for the support of others who share my problem. It’s been important for me to set boundaries. I used to just let others go on and on about their religious convictions, but now I politely stop them and let them know I’d rather discuss something else.