So how does a person shut down conscience? Two ways: misinform it. Conscience is not a law; conscience is a mechanism. You can shut down pain, right? You can shut down pain; just take drugs. Mask pain. If you mask pain, you mask the reality that you’re doing some damage. You can mask conscience by misinforming it. How do you do that? You take the true law of God, which is written in Scripture and written in the human heart, and you basically eliminate it, denounce it, diminish it, remove it, and replace it with another law; and if you do this generationally you’ll eventually raise generations of people whose conscience is now informed by lies. The other thing you can do to shut down the conscience is just think you shouldn’t feel guilty. Let psychology take you off-the-hook: “You shouldn’t feel bad about yourself. You’re wonderful. You’re the best. You can be anything you want to be. You’re heroic. You’re a good person. You ought to be able to do whatever you want. You live any way you want. Don’t let anybody make you feel guilty for anything.” Just keep driving all efforts against the normal work of the conscience and misinform the conscience and you’ve turned the beast loose. This society in which we live today has been doing that damage for decades, for decades.
John MacArthur