The law of God had a definite function in the history of redemption. It still has a function, but it is not the same function as it had in Israel’s experience. The law that worked wrath in Israel’s conscience has been fully silenced and does not work, in any sense, either wrath or blessing in the Christian. The law of God can neither curse nor bless a Christian. It cannot curse a Christian because Christ has endured every curse the law threatened, and it cannot bless a Christian because even with a new heart, the child of God cannot earn the blessing that is the reward for perfect obedience. However, just as Christ endured every curse the law threatened, he also earned every blessing the law promised. If you read the law and feel guilt and despair, you do not understand justification, and if you read the law and feel good about your progress in sanctification, you are a deceived, self-righteous hypocrite.
The law…is not for the righteous. Righteousness comes by faith, not by performing works of the law. Therefore, it is wrong to make the law our “savior or judge,” as Bunyan affirmed. However, it is not wrong for us to allow the law to “instruct our minds,” as long as we filter that instruction through the New Covenant. The final, authoritative, yardstick that validates any truth or law for the child of God is the gospel.
Legalism…does not describe the attitude of a Christian who earnestly seeks to please God, but uses the law as a means to that end. A sincere desire to please God is not legalism. Nor does it cause legalism. Legalism results from the actual misuse of the law. Nor does legalism in any sense diminish the goodness of the law. There is nothing wrong with God’s holy law. Woe to the person who disparages the holy law that God wrote on stone with His finger.
Conscience is not a lawgiver. It does not teach us what is right and wrong. It functions as a judge to apply the law that has been given to it. Conscience is not an infallibly safe guide, because it can be trained to obey wrong standards. Some people can commit the most horrible deeds and feel they are doing what is right (John 16:1–3).
Conscience does not, and cannot, tell you what is, or is not, the right thing to do. That is the role of parents, society, education, and for the Christian, the Bible. All human beings have a conscience, but the law that a specific conscience uses to accuse or excuse certain actions or intentions will vary greatly according to the individual’s environment and background. Obviously, the higher the standard that trains the conscience, the more conscience will “accuse.” When the law of God trains the conscience, it is impossible for that conscience ever to approve completely, since that law demands sinless perfection.