Chrysostom said that conscience and nature are two books in which the human mind can read of God previous to supernatural revelation. The conscience is like a flashing light on a highway. We may ignore it, or we may get mad at it, but those who pay no attention to it will often pay severe consequences.
No one doubts that a flashing light had a designer. The conscience is our flashing light – our warning device. If God did not give it to us, where did it come from?
The conscience is the mind acting as a judge. It is “what feels bad when everything else feels so good.” A dieter who yields to temptation and gobbles a cake knows this feeling. So do sinners.
Some people think a good moral man can simply follow his conscience and be saved. Paul could say to his Jewish family, “…I have lived before God in all good conscience until this day” (Acts 23:1). Though his conscience was his guide, a mind can judge only what it has learned. Paul’s unenlightened conscience moved him to persecute Christians. In fact, his conscience would have hurt if he had not tried to destroy the Lord’s people. “Indeed, I myself thought I must do many things contrary to the name of Jesus of Nazareth. This I also did in Jerusalem, and many of the saints I shut up in prison, having received authority from the chief priests; and when they were put to death, I cast my vote against them. And I punished them often in every synagogue and compelled them to blaspheme; and being exceedingly enraged against them, I persecuted them even to foreign cities” Acts 26:9-11.
A good conscience is no guarantee against eternal condemnation. “For I know nothing against myself; yet I am not justified by this; but He who judges me is the Lord” (1 Corinthians 4:4). Paul knew that “good conscience” and “chief of sinners” once lived in the same man. They still can. –Rick Duggin