Becoming a Better Sinner

My name’s Ron and I’m a sinner. I'm being changed by God but still have a nose for temptation, like a smoker for a cigarette. So...what's with David, from the Bible? Quite a sinner: killed his friend after bedding his wife. Yet the Bible calls him “a man after God’s own heart”. Somehow God considered David a better kind of sinner. That's what I want to become. Care to join me?