i could write a (good) book on this subject. I'm an ahtiest myself and I worked AA/NA for about all of 3 months until I realized that it was doing more harm than good.
it's not even the whole GoD concept.. i'm grounded enough in my beliefs where I could honestly care less what other people say or do.
No, what got me is the mixed messages of NA/AA. you come in and it's a spiritual program not a religious one. then once you get to how it works, it's "the answer is god, let him find them now". Bill wilson rips off quotes from the Divine Comedy, goes from it's a "disease" to saying that "bottles were only a symptom" and I can go on and on.
What pisses me off is they are more concerned about the program than they are about you staying clean. you can stay clean for 6 years but ifg you aren't in NA/AA you are a dry drunk, whereas if you realaspse 5 times in 3 months you are working the program as long as you are in NA/AA. I got tired of it. I reazlied no, I didn't want what they had, and left.