I'm sure that believing in a god is a great motivator and it gives a person a higher power to look to for support. I was a very addicted smoker and had to give cigarettes up to become a Jehovah's Witness. It was a dreadful experience (yes, being a JW was a dreadful experience too) but my wish to please god pushed me through barriers that I could never have motivated myself to overcome just for my own sake. I've never heard of a similarly powerful secular alernative to the 12 steps but it would be great if spirituality was powerful enough to motivate without the religion bit. I suspect that a belief in the afterlife is part of this spirituality.