There is a section of the two-part hour long sermon that made me think of a Bob Newhart skit. In the skit from MadTV, Newhart is a psychologist seeing a patient for the first time. Now, here is the salient part of MacArthur's sermon about sin:
"Now what is he [Paul] saying? I'll tell you what he's saying. Stop lusting. It's not too mystical. Stop lusting. It's like 1 Corinthians 6:18, "Flee immorality." Do you want to put to death the lusts in your heart? Then stop entertaining them. Peter doesn't describe some complex program of therapy, he says quit lusting. Stop it. Put it out of your life. There's no point sitting around waiting for some heavenly power to erase lust. There's no point spending hours and hours or years and years looking for the right formula to chase away the demon of lust. Here's a most simple straight-forward means of killing sin, stop lusting...stop it. It's kind of like James 4 which says resist the devil and he'll flee from you. Stop lusting and you'll stop sinning."
Here is the Newhart piece which I believe makes a great companion to the MacArthur point about sin. Watch the first 2:40:
LOL! If you want to get the impact of the point, then listen to MacArthur's full part one of 'Hacking Agag to pieces'. Then think of the Newhart skit. We laugh at the moment when Newhart says "STOP IT!" but there is truth to those words. We engage in self-indulgent therapies for sins we maintain are generated outside of our bodies, not inside. We let them linger, run around, placate them because those sins are 'not our fault'. But MacArthur is right. There is no complex therapy that will help us stop sin. There is no divining rod to pass over us to erase it. It is up to us to stop it at the root. And that root is our thoughts. Do not think about your lusts. Do not entertain thoughts of them. STOP IT.
"Easy for you to say that!" you might make a charge against me. But I've been there. I'm still there. I have to work really really hard at not letting sinful thoughts enter into my head. When I find them, I have to work at telling my brain to "STOP IT". It's work. Paul said in Romans 6:12 "Therefore do not let sin reign in your mortal body, that you should obey it in its lusts." Do not. It is as simple as that. "Present yourselves to God as being alive from the dead, and your members as instruments of righteousness to God." If you put on your armor, resist the devil, and guard your thoughts, "For sin shall not have dominion over you, for you are not under law but under grace." (Romans 6:13b-14). And that is a very good place to be.