I love this thread!
This issue of a higher power has been my biggest hurdle in Al Anon. I too don't believe an a supernatural god. I know that there are many forces in the universe far more powerful than I. I just don't think that those forces have any awareness of me or my problems.
Yet, Al Anon has been my anchor since I found it. I've found a number of groups that work for me. And for me, it has been through the power of the group that I've had the support to do things that I wouldn't have easily done on my own. I don't necessarily 'give' anything to the group (as in giving something up to god). But I know that in sharing my experience and asking for help I get the peace and confidence to do what I need to do.
If someone gets on a religious tangent, I just look at it as if I'm at a wedding at someone else's church. I can respect them and allow them their beliefs. I guess that's my little way of letting go.
We're social creatures. We've always survived better in groups. The Al Anon group serves that same wonderful purpose.
I can't lift a refrigerator. But with a group of friends it's easy. Simple yes, but it works for me.
I hope lots of other folks post on this topic!