by John MacArthur
In 1984, an Avianca Airlines jet crashed in Spain. Investigators studying the accident made an eerie discovery. The “black box” cockpit recorders revealed that several minutes before impact a shrill, computer synthesized voice from the plane’s automatic warning system told the crew repeatedly in English, “Pull up! Pull up!”
The pilot, evidently thinking the system was malfunctioning, snapped, “Shut up, Gringo!” and switched the system off. Minutes later the plane plowed into the side of a mountain. Everyone on board died.
When I saw that tragic story on the news shortly after it happened, it struck me as a perfect parable of the way modern people treat the warning messages of their consciences. The wisdom of our age says guilt feelings are nearly always erroneous or hurtful; therefore we should switch them off.
But that kind of thinking betrays a deep misunderstanding of what the conscience is and how it works. Your conscience isn’t the voice of God or the law of God. It’s not an external force of any kind.
As the Puritan Richard Sibbes wrote, the conscience is "the soul reflecting upon itself."1 Richard Sibbes, Commentary on 2 Corinthians Chapter 1, in Alexander B. Grosart, ed., Works of Richard Sibbes, 7 vols. (Edinburgh: Banner of Truth, 1981 reprint), 3:208. Put another way, it is the human faculty that judges our actions and thoughts by the light of the highest standard we perceive. Like any warning system, it needs to be programmed—it needs to be taught and trained to discern right from wrong before it can be fully effective.
That’s why a Mormon’s conscience binds him to the ceremonies and rituals of the Mormon faith. It’s why a Catholic’s conscience binds him to the pope, the saints, and the sacraments of the Catholic Church. Your standard for morality—whatever it is—will shape, guide, and direct your conscience.
Therefore, it’s absolutely crucial to establish the Lord’s holy standard for purity and godliness in your own heart. Anything less will lead you to have a weak, shallow conscience that regularly permits you to fall short of God’s commands.
Or worse—it could lead you to sin. If you subscribe to the world’s no-shame, man-centered standard, your conscience can actually encourage you to sin. It can become so perverted and twisted that it makes you think you ought to be lying, cheating, and gossiping. It might even make you believe, as many people do today, that there is something wrong with you if you’re not regularly getting drunk, defrauding people, and having sex outside of marriage.
The fastest way to turn yourself over to the corruption of the world is to adopt its faulty, post-modern standard of morality and pervert your own conscience.
Instead you need to guard your conscience and protect it from the pollution of the world. You need to feed it regularly on the rich truth of God’s Word, establishing His perfect law as the standard for your life. You do that through faithful personal Bible study, consistent intake of quality teaching and exhortation from Scripture, godly accountability and persistent self-examination.
The Lord gave you a conscience to help protect and defend you spiritually. But you’ve got to protect and defend your conscience if it’s going to do you any good.