This quote from Marijuana Anonymous’ book Life with Hope, page 7 (Step Two) sheds light on this question:
It is not necessary to acquire a major God Consciousness to be able to cease using. All we need is to maintain an open mind and a hopeful heart. It is not necessary to say yes. It is, however, important to stop saying no. Observe the reality around you and the recovery taking place within MA. One only has to stop fighting. Higher Power means different things to different people. To some of us, it is a God of an organized religion; to others, it is a state of being commonly called spirituality. Some of us believe in no deity; a Higher Power may be the strength gained from being a part of, and caring for, a community of others. There is room in MA for all beliefs. We do not proselytize any particular view or religion. In MA each of us discovers a spirit of humility and tolerance, and each of us finds a Higher Power that works for us.