The Importance of Maintaining A Good Conscience
Martin Luther believed that maintaining a good conscience was worth going to prison for and even dying for. That great Reformer discovered in the Bible that God justifies sinners by grace alone, through faith alone, in Christ alone. The Roman Catholic Church excommunicated Luther and demanded that he recant his writings, but at Luther’s hearing before the Diet of Worms, he refused to go against his conscience, even if it meant death: “Unless I am convicted by Scripture and plain reason—I do not accept the authority of popes and councils, for they have contradicted each other—my conscience is captive to the Word of God. I cannot and I will not recant anything, for to go against conscience is neither right nor safe. God help me. Amen.”
Luther offers a timeless principle: You should maintain a good conscience even if it means you’ll suffer prison or death. It’s that important. And that’s why it’s so important that you learn how your conscience works and how you may need to adjust it. It would be a shame to go to prison or die because you held a conviction based on a misinformed conscience.
Is Your Conscience Perfectly Reliable?
No one’s conscience perfectly matches God’s will in this life. Nevertheless, we believe that you should generally always follow your conscience. “Generally always?" Yes, that’s the general rule, so that’s what we should emphasize. God didn’t give you a conscience so that you would disregard it or distrust it. Romans 14:22b–23 teaches that a person who lives according to their conscience is “blessed.” So the general principle, especially for Christians who have the Holy Spirit and the holy Scripture, is that you should listen to and obey your conscience. As a general rule, you should assume that your conscience is reliable, even if it isn’t perfect. And since conscience is usually right, the Bible says that we should do what our conscience says until we are convinced from Scripture that it needs adjusting.
So the general principle, especially for Christians who have the Holy Spirit and the holy Scripture, is that you should listen to and obey your conscience.
But your conscience is not identical to the voice of God. That voice in your head is not necessarily what God would say. So how do you cultivate a conscience that aligns with God’s voice?
Calibrating Your Conscience
You probably know what it means to calibrate an instrument such as a scale or clock or speedometer. After ten years as a one-car family, my wife and I (Andy) recently joined the “swagger wagon” club and bought a minivan. I soon noticed that the van’s speedometer routinely reads about four miles per hour faster than the speed that our GPS indicates. I discovered that the manufacturer intentionally calibrates the speedometer to read three or four miles per hour faster than the actual speed. Even more frustrating, I can’t find a way to recalibrate the speedometer other than buying larger tires. Not even the dealership will touch it. Or let’s say you weigh 110 pounds. If you step on a scale and that scale reads 115 pounds, then that scale is off by 5 pounds. Someone needs to calibrate it so it functions accurately. That’s essentially what calibrating is: aligning an instrument with a standard to ensure that it is functioning accurately. Your conscience is a part of you that functions like an instrument, and it doesn’t always function accurately. So you need to calibrate your conscience to align it more closely with the standard of God’s Word.
The Example of Peter
Does the Bible include any examples of someone calibrating their conscience? Yes. This is exactly what Peter had to do— rather quickly!—in Acts 10:9-16. God gave Peter a vision of certain kinds of animals that the Old Testament forbade Jews to eat. But in the vision, the Lord Jesus said, “Kill and eat.” Peter’s weak conscience revolted against this command: “By no means, Lord; for I have never eaten anything that is common or unclean.” Clearly, Peter’s faith in Christ was not weak; he was an apostle who understood and believed the gospel. Thousands had converted under his preaching, and he had even suffered for the gospel. Yet when it came to eating unclean animals and fellowshipping with Gentiles, Peter’s faith was still very weak indeed, in the sense that he lacked confidence to do these things. But because Christ himself was commanding him, he had to calibrate his conscience so that he would have the faith (confidence) to accept food and people that he was previously not able to accept.
How Do You Calibrate Your Conscience?
So how should you calibrate your conscience? We suggest two basic principles:
Calibrate your conscience by educating it with truth. As best you can, try to discern why you hold certain convictions. Is it based on truth, especially the truth God has revealed in Scripture? Here’s how John MacArthur puts it in his book, The Vanishing Conscience: "The conscience reacts to the convictions of the mind and therefore can be encouraged and sharpened in accordance with God’s Word. The wise Christian wants to master biblical truth so that the conscience is completely informed and judges right because it is responding to God’s Word. A regular diet of Scripture will strengthen a weak conscience or restrain an overactive one. Conversely, error, human wisdom, and wrong moral influences filling the mind will corrupt or cripple the conscience. In other words, the conscience functions like a skylight, not a light bulb. It lets light into the soul; it does not produce its own. Its effectiveness is determined by the amount of pure light we expose it to, and by how clean we keep it. Cover it or put it in total darkness and it ceases to function. That’s why the apostle Paul spoke of the importance of a clear conscience (1 Tim. 3:9) and warned against anything that would defile or muddy the conscience (1 Cor. 8:7; Tit. 1:15)."
Calibrate your conscience with due process. This is a wisdom issue. Sometimes it will take a lot of time to work through a particular matter. The example of Peter in Acts 10 is unusual because God directly commanded him to do something that his conscience previously prohibited him from doing. As a mature Christian, Peter was able to calibrate his conscience on the fly. But sometimes it can take us years to calibrate our conscience on a particular issue. And Peter’s failure many years later to eat with the Gentiles in Antioch when under pressure reminds us that sometimes recalibration is necessary (Gal. 2:11–14).
This education is not something you do in a vacuum or all alone. God has put you into a community and given you various relationships of accountability, especially your family (if you’re young) and your church. Godly church leaders will help you discern the difference between issues of right and wrong and issues of preference or scruple.
This article is adapted from Conscience: What It Is, How To Train It, and Loving Those Who Differ by Andrew David Naselli and J. D. Crowley.
 Roland H. Bainton, Here I Stand: A Life of Martin Luther (New York: Abingdon-Cokesbury, 1950), 182 (italics added).
 John MacArthur, The Vanishing Conscience, 39.