“People sometimes pray over and over to be delivered from a bad habit or an addiction, but are not freed from it. And they become discouraged when God doesn’t answer their prayer. Here’s why that happens. Whenever prayer is not delivering us from the sin or passion we’re praying to be rid of it’s because that sin is anchored by some other sin underneath it, like a boat being held in check by a submerged weight. For example (as we’ll see later on), underlying an addiction to food or alcohol is the big passion of Self-Love. So we often need to pray for God to deliver us from Pride and show us the deeper sin anchoring the one that’s a problem.
“When we pray for God to show us what sin is underlying the difficult, involuntary sin we can’t overcome, it will always bring us to some voluntary sin we can get hold of and repent, an anchor we’re able to pull up. In that way, even persons who are very weak, say the saints, will find a point where they can begin to turn themselves around and change the whole course of their lives. Mark the Ascetic writes, According to Scripture, the cause of all sin that is involuntary lies in what is voluntary.
He who is drawn away by sin against his will ought to understand that he is being mastered by some other previous sin, which he serves willingly, and is henceforward led under its power even to things which he does not wish.
— Basii the Great
[Taken from Dee Pennock’s Path to Sanity]