great article on why both legalism and licentiousness stem from a serious misunderstanding of the nature of sin.
Legalism vs Licentiousness
The legalist believes he can avoid sin, and manage (if only occasionally) to live sinlessly. If he is right, then the legalist doesn’t need the sinlessness of Jesus, or if he does, he only needs it when he fails to avoid sin. The licentious person believes he has permission to sin. If he is right, then the licentious person doesn’t need Jesus to suffer the penalty for his sin.
What comes next is counterintuitive. Many preachers think that they can cure people of licentiousness by preaching the Law more. This is a good first step, but the Law is only the diagnosis and prognosis. The Law alone isn’t the cure for licentiousness. Preachers sometimes think that Legalism can be cured by really driving the Law home to those who think they are keeping it. Again this is a good first step, but the Law alone cannot cure Legalism either. Why are our churches filled with both the legalists and the licentious? Because our pulpits are not filled with both Law and Gospel.