Paul wrote, “For our rejoicing is this, the testimony of our conscience, that in simplicity and godly sincerity, not with fleshly wisdom, but by the grace of God, we have had our conversation in the world, and more abundantly to you-ward” (2 Corinthians 1:12). The word “conscience” basically means “with knowledge.” The conscience is a human being’s “moral” guide, giving feedback as to what is right and wrong. A favorite question has always been, “Can we trust the conscience?” The Bible teaches that man cannot fully trust his own guide because it is not infallible. Proverbs 14:12 says, “There is a way which seemeth right unto a man, but the end thereof are the ways of death.” A way that seems right (by the conscience) can end in death. Paul even proved that a man can live with a good conscience while still being wrong (Acts 23:1).
The conscience is a witness. Romans 2:15 says, “Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another.” Romans 9:1 adds, “I say the truth in Christ, I lie not, my conscience also bearing me witness in the Holy Ghost.” The conscience can only know and witness what it is taught, therefore, if it is taught inappropriately, it will not be an acceptable witness.
The kind of witness a Christian projects directly depends upon what kind of conscience they possess. For instance, a good conscience provides a good witness. Peter said, “The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ” (1 Peter 3:21). While the world loves to accuse others, the conscience strengthens its owner by testifying to him that he is not guilty of the sins of the world. Paul testified, “I thank God, whom I serve from my forefathers with pure conscience, that without ceasing I have remembrance of thee in my prayers night and day” (2 Timothy 1:3). A pure or clear conscience will always return a favorable witness or result. Hebrews 9:9 says, “Which was a figure for the time then present, in which were offered both gifts and sacrifices, that could not make him that did the service perfect, as pertaining to the conscience.”
This verse further implies that a perfect conscience is a perfect witness. The ordinances of the Old Covenant had been external. They had not been able to come to grips with the real problem: a troubled conscience. The Old Testament worthies never could obtain it by the sacrifices, but because the blood of Christ has taken away man’s sins, his conscience testifies that his record is now clean (Hebrews 9:14).
A defiled conscience produces a defiled witness. Paul said in 1 Timothy 4:2, “Speaking lies in hypocrisy; having their conscience seared with a hot iron.” The word “seared” means that the conscience has become insensitive. If the conscience has been abused, it is no good. Those who had fallen away in their hypocrisy no longer had any feeling. Hebrews 10:22 says, “Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.” The evil conscience produces an evil witness. The conscience is evil because it must constantly tell its owner that he is guilty. The writer of Hebrews showed that doubt or hesitation, leading to unbelief, would produce an evil conscience.
Finally, a weak conscience is a weak witness. Paul said in 1 Corinthians 8:12, “But when ye sin so against the brethren, and wound their weak conscience, ye sin against Christ.” The weak conscience is too poorly informed to know what to say. Every single person must be careful about living by their conscience. As has already been noted, different consciences make different guides. More times than not, the conscience is not trustworthy unless it has been taught by the word of God. The Bible is the only plan which man can stand upon. Anything else is risky business.