Every so often I have to re-read this great comment from A.W. Tozer from his Pursuit of God:
"The man who has struggled to purify himself and has had nothing but repeated failures will experience real relief when he stops tinkering with his soul and looks away to the perfect One. While he looks at Christ, the very things he has so long been trying to do will be getting done within him. It will be God working in him to will and to do."