He's an expert on bondage. Unfortunately for him, it's his own bondage, and he doesn't know how to get free. If you give in to it, it wraps another cord around you, making it tougher for you to fight back the next time. And every time you sin, it becomes harder for you to resist and easier to yield. You get weakened, and you lose your resolve to fight.
Sin leads to worse sins.
This principle is absolutely terrifying. It's bad enough that sin leads to more sin, that one drink leads to another, that one immoral act leads to another. But it's even more sobering to realize that sin always drags the human character and will down, never lifting it up. The serial killer started somewhere perhaps with fits of disobedience when he was a child, perhaps with being cruel to his pet cat, perhaps with a sexual fetish before becoming a monster capable of taking innocent human lives. Sorry, pastor, but your examples of drug addicts and serial killers have nothing to do with me.