There are plenty of atheists in AA. When I decided to become sober, I was lost, demoralized, without purpose, and had absolutely no idea how to change it all. To me, the steps can provide me with a life purpose and specific actions I can take. When I work through those actions, I begin to address my problems and resolve them - in turn, I start to rebuild self-esteem, self-respect, and a sense of responsibility for my actions.
That said, AA is definitely not the only way. SMART has a completely different set of tools that you can use, or LifeRing has as "programless" approach. How much structure do you think you need to stay sober?