Paul was always exercising and exerting himself to have a good conscience (Acts 24:16). The word here for “exercise” is the word for a gymnast’s or athlete’s activity. It is also used of a drill sergeant. In other words, Paul was always stirring up his conscience to action; he was making it think and work. He was challenging it, prodding it, training it, and calling it to action.

The muscle of conscience
Paul really portrayed the conscience like a muscle that has to be exercised to be healthy. And he exercised it “always.” He never let his conscience become lazy, or sleepy. He knew that, like his body, the more he exercised his conscience, the happier and healthier he would be. Paul was not a Sunday jogger. He never had a day off. In every area of life he was prodding his conscience, stirring it up, commanding it to speak: “Is this right or wrong, true or false, good or bad? What should I do with this church? What should I do with my money? What should I say to this person?”

But he went on to say that he exercised it for a purpose. He was not just exercising conscience for fun, or as a philosophical pastime. It was not enough for Paul to have an internal debate or discussion; right action had to follow. His aim was that his conscience would be literally “without a stumbling block.” He was picturing his good conscience as a runner moving swiftly along a smooth road without obstacle, impediment, or pain. But when conscience is rejected and disobeyed, it’s like running into a sharp piece of rock that bruises and bloodies us. Thank God he makes us feel pain in our consciences when we sin, so that we are stopped from going further.

A seared conscience
And at that point we have two options. We can ignore the “pain” and carry on regardless. If we do, we will end up with a seared and calloused conscience (1 Tim. 4:2). The “scar tissue” will thicken and we won’t feel the pain so much the next time. We will be able to go further and more comfortably into sin. Izaak Walton said, “The person that loses their conscience has nothing left worth keeping.”

Or, we can take our painful, bleeding wounds to the bleeding wounds of Christ (Heb. 9:14; 10:22). His blood can purge and heal our consciences. And not only that, if we remove the pains of our bleeding conscience via the blood of Christ, we end up with a conscience that is even more sensitive than it was before we sinned.

If we exercise our conscience in one area of life, we will strengthen it for all other areas of life. But if we offend it without repenting in one area of life, we will be desensitized in every area of life. If we steal from our employer, it becomes much easier to abuse alcohol, and commit sexual sin. If we give up one doctrine, (e.g. the creation of the world in six days), it becomes much easier to give up other doctrines (e.g. the historical Adam, etc.).

A saved conscience
If we have calloused and seared our consciences, the way to re-sensitize it is to bring it back to the blood of Christ (Heb. 9:14; 10:22). In fact, daily application to Christ’ blood is an essential element in the exercise of a good conscience.