The author writes about renunciation, says that when you give something up--alcohol, drug, person--it leaves a void inside of you that something else will rush in to fill. Augustine's God-shaped hole. But some people, she says, realize the emptiness itself is God. That a Zen master once described enlightenment as Lots of space and nothing holy.
Brain scans show believers react with less stress to their mistakes than atheists. Regardless of where one is on the metaphysical vs supernatural feeling of what God is, feeling like something is in control seems to be a useful point of view.