I often think that step two, "Came to believe that a Power greater than ourselves could restore us to sanity" is the point where we can accept or reject the AA spiritual solution. If one was not even willing to believe, then the mind is closed to the possibility of experiencing such a power working for us and there wouldnt be any point in pursuing the AA solution.
One can just as easily come to believe any number of other things will solve the problem. One such belief could be "that I have sufficient power to keep myself sober in all circumstances." Though a delusion for me, this would be realistic for many problem drinkers.