Conscience: What It Is, How to Train It, and Loving Those Who Differ

by D.A. Carson

How can you discern between your conscience and the Holy Spirit? You can’t know infallibly. But you can know when it is not the Holy Spirit: if the message contradicts Scripture, then it is not from the Holy Spirit but from your wrongly calibrated conscience. But when the message is consistent with Scripture, the Holy Spirit is likely working through your conscience.

Of all the principles related to conscience, two rise to the top: (1) God is the only Lord of conscience, and (2) you should always obey your conscience.

The Bible teaches in Romans 14 and 1 Corinthians 8 that to go against your conscience when you think it’s warning you correctly is always a sin in God’s eyes. Always. Even if the action is not a sin in and of itself. Why? Because your intention is to sin. But does this mean your conscience is always correct? No. And this brings us to the first principle of conscience.

This means that the second principle (obey conscience) has one critical limitation. If God, the Lord of your conscience, shows you through his Word that your conscience is registering a mistaken moral judgment and if you believe he wants you to adjust your conscience to better match his will, your conscience must bend to God.

In the New Testament conscience translates syneidēsis, a word that occurs thirty times in the Greek New Testament. Conscience is also one of the few theologically significant New Testament words that lacks a parallel word or group of words in the Hebrew Old Testament.

The conscience is your consciousness of what you believe is right and wrong.6 Consciousness means awareness or sense, and we include that word in the definition to make it more memorable.

Martin Luther’s famous statement nails it: “My conscience is captive to the Word of God.”

2. Conscience can change.

3. Conscience functions as a guide, monitor, witness, and judge.

This word: God so loved the world that he gave his one and only Son to redeem all who trust in Christ. God forgives and covers all their sin, and he never counts that sin against them for all eternity because he counted that sin against Christ instead. Only this message can comfort a non-Christian’s guilt-racked conscience.

Only the cross can fill that ever-widening gap between your consciousness of what you ought to be and your actual obedience. As you mature in your faith, you grow increasingly in love with Christ and his gospel; you place your trust more and more in Christ to make you acceptable before God; and you wait with greater and greater anticipation for the day when Christ will come back and make your obedience match your knowledge.

“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.”2 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.

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.

Your conscience is not identical to the voice of God. That voice in your head is not necessarily what God would say.

Having said that, it’s also clear from Romans 14 that the strong in faith do not necessarily please God any more than the weak in faith. Both can glorify God, and both can sin against God.

If you think that it’s wrong to drink root beer, then you are sinning if you drink root beer. As Mark Dever puts it, “Conscience cannot make a wrong thing right, but it can make a right thing wrong.”

When we form convictions about what we believe is right and wrong, we must take into account truth in two spheres: (1) truth inside the Bible and (2) truth outside the Bible.

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.

Here’s the gist of what Paul told those with a strong conscience (column 1): “You can continue to use your freedom because in principle you’re right about these issues. But what you must not do is look down on (i.e., despise) the strict. You must welcome them, learn how to get along with them, and learn to appreciate their subculture. You need to assume that they’re being strict for God’s glory, not because they’re neurotic fundamentalists.

“If your strictness in these matters is causing you to judge others and bring division to the church, you are sinning and failing to show love. The kingdom of God is about love and righteousness and peace and joy, not about food (14:17). And one more thing: stop trying to force others to obey the rules of your conscience. Your conscience is for you, not them. Welcome those who disagree with you on food and drink and holy days. Learn about them. Appreciate their robust conscience. Assume that they are exercising their freedoms for God’s glory.

In their book Ethics for a Brave New World, John and Paul Feinberg suggest “eight questions (tests) that each Christian must face when deciding whether or not to indulge in a given activity”:14 1. Am I fully persuaded that it is right? (Rom. 14:5, 14, 23) 2. Can I do it as unto the Lord? (Rom. 14:6–8) 3. Can I do it without being a stumbling block to my brother or sister in Christ? (Rom. 14:13, 15, 20–22) 4. Does it bring peace? (Rom. 14:17–18) 5. Does it edify my brother? (Rom. 14:19) 6. Is it profitable? (1 Cor. 6:12) 7. Does it enslave me? (1 Cor. 6:12) 8. Does it bring glory to God? (1 Cor. 10:31)

If you want the hearer’s conscience to powerfully affirm your gospel witness, you must (1) preach repentance from sins that are clearly sins in both the Bible and the consciences of the people in the target culture and (2) cultivate those virtues of the target culture’s conscience that are not traditionally a part of yours.

Because God created us in his image, we can expect all cultures to have good, wholesome values and traditions that we can wholeheartedly affirm and learn from. But because humans are also fallen, we can expect all cultures to have values and traditions that displease God.

Priest recommends that if a missionary wants to reach people in other cultures, he or she should (1) “seek to live an exemplary life in terms of the virtues and norms stressed by the people he or she is attempting to reach” and (2) “should stress sin, guilt, and repentance principally with reference to native conscience—particularly that aspect of their conscience which is in agreement with Scripture.”10