I have friends who have done very well in Women for Sobriety and Rational Recovery. I also have atheist and agnostic friends who have done well in AA. They use "the universe" or "physical laws" as their higher powers. One guy even uses "Jung's Archetypes" as his higher power, saying it's too complicated to explain, but it makes sense to him. Several of these folks have had very bad experiences with organized religion. They approached AA with a combination of trepidation, resistance and defiance because of AA's spiritual approach.

They seemed to do well because they had wise mentors and sponsors in the Program who told them to look at the Promises and Traditions as well as the Steps, specifically the part about the importance of Program over Personality.

It's not unusual to find a few members who act more spiritual than thou, who take to preaching about their particular version of God instead of talking about the overall program. By remembering that the whole program is more important than the actions of a few annoying members, my non-believing friends were able to get beyond their resistance, get sober and stay sober, while enjoying the fellowship AA offers.

Most of them got stuck a Steps 6 and 7, but a lot of believers get stuck there, too, waiting for God to perform some kind of miracle. But they found ways to not make the words too literal or concrete and moved on to the other steps after letting go of resistance with the help of accepting sponsors.

They experienced a level of spirituality (which was maybe the dropping away of ego and losing resentment at religion) while maintaining their atheism and tolerating fellow members who maybe got carried away with their own ideas about God. And they're still sober.

In my experience, it is possible for non-believers to benefit and enjoy AA. They may have to search around to find a compatible meeting. But that may be true for the majority of people