We have so far considered three foundations for ethics, three means by which we are to distinguish between right and wrong, three ways by which to judge between good and bad living. These three are the law of God, the guidance of the Holy Spirit, and, the subject of our last Lord’s Day evening study, the example of the Lord Jesus Christ.

Tonight I want to go on a fourth foundation of ethics as taught in Holy Scripture, namely the conscience.

There is much less attention to the conscience than was once the case in Christian teaching and preaching. The Puritans, for example, made a great deal of the conscience, and so did many of the greatest preachers of the gospel through the centuries. They appealed to it as the very voice of God within a man or woman.

Appeal has been made to the conscience as well as an evidence of the existence of God and our being his creation. As C.S. Lewis has argued in various works, the conscience cannot be a product of mere nature, another human instinct. “This thing that judges between two instincts, that decides which should be encouraged, cannot itself be either of them. You might as well say the sheet of music which tells you, at a given moment, to play one note on the piano and not another, is itself one of the notes on the keyboard.” “There is no escape…. If we are to continue to make moral judgments (and whatever we say we shall in fact continue) then we must believe that the conscience of man is not a product of nature. It can be valid only if it is an offshoot of some absolute moral wisdom, a moral wisdom which exists absolutely ‘on its own’ and is not a product of non-moral, non-rational nature.” (Mere Christianity, pp. 22-23; Miracles, p. 38)

Lewis says this because, of course, it is a universal human experience that the conscience is largely autonomous in its operation. Though sometimes we can suppress it or silence it, it normally speaks independently of our will, sometimes rides roughshod over our will, contradicting, accusing and condemning the course of action we wish to take. And when it speaks to us — often making us quite miserable, often making us wish we could shut it up — it is, in a strange way, distinct from us. It stands over us and, often, against us, addressing us with an authority we did not give it and cannot take from it.

The Puritans, for example, referred to the conscience as “God’s deputy and vice-regent within us,” or “God’s spy in our hearts,” or “God’s sergeant he employs to arrest us,” or “God’s court within us.”

The word conscience comes from two Latin words: “con” meaning “with”; and “scientia” meaning “knowledge.” That is, the conscience is a shared knowledge, as the old writers thought, a knowledge we have together with God. Thomas Aquinas defined the conscience as “Man’s judgment of himself according to the judgment of God of him.” In all likelihood, the original sense is rather a knowledge shared with oneself, a self-knowledge in which the inner self comes forward as a witness or a judge. But that does not exclude the first idea, because, as we shall see, the knowledge that the inner self possesses and bears witness to is exactly that knowledge of the divine law and the divine will that has been implanted in the heart of all those who have been made in God’s image.

Now it is clear that the conscience is to be a foundation of ethics, that is to day, a means by which to determine what we are to do and how we are to live. And the simple demonstration of that is Paul’s statements in 1 Cor. 8, 10, and Rom. 14 that even when the conscience is in error in the judgments it passes upon a man’s behavior, the man is still to be condemned for violating his conscience. As Paul puts it in Rom. 14:23:

“…the man who has doubts is condemned if he eats, because his eating is not from faith; and everything that does not come from faith is sin.”

The conscience, in other words, is a form of rule, of divine rule in our hearts.

The fundamental passage on this theme is Romans 2:14-15:

Indeed, when Gentiles, who do not have the law, do by nature things required by the law, they are a law for themselves, even though they do not have the law, since they show that the requirements of the law are written on their hearts, their consciences also bearing witness, and their thoughts now accusing, now even defending them.

Paul here makes the following assertions:

1. The divine law has been written upon the hearts of all.
2. The conscience is the moral faculty that bears witness to that law.
3. In the light of that witness there is an experience of
moral judgment that is common to all men.
4. The result of that moral judgment is that men are subject
to moral self-approval or self-reproach.

Now, there is nothing particularly controversial in this except, of course, the assertion that God’s law is written upon the heart. Unbelievers are less likely to admit that. But, everyone is well enough acquainted with the human reality of a conscience speaking, the inner witness being born to right and wrong. We are acquainted with both the way in which it speaks and the power with which it speaks.

Think just of the Book of Acts and the many examples of conscience asserting itself. The book begins with Judas’ terrible remorse and his suicide. That was Judas’ conscience that drove him to that, a conscience that would not let him evade his responsibility for Jesus’ murder. [Liberal jurisprudence in the USA for years now has been deeply suspicious of confessions, but, for all its efforts to protect suspects from any pressure to confess to the crime, confessions continue to be made, many are blurted out without thought to the consequences. The conscience is a greater power than the fear of punishment!] Or think of the men “cut to the heart” under Peter’s preaching: “What have we done?” And, “how might we then be saved?” This is the conscience forcing upon them the recognition of their own evil and the enormity of the crimes they had committed against God and man.

In John Henry Newman’s verse:

Thus the Apostles tamed the pagan breast,
They argued not, but preached, and conscience did the rest.
[Whyte, Bunyan Characters, iv, p. 47.]

And so conscience has continued to rule the hearts of men ever since. Think of Augustine in agony in the Milanese garden or John Bunyan unable to get a moment’s peace from his conscience first as he fell under the power of the Gospel and on into the first year and half of his Christian life.

Just imagine how you might live, what you might do and what you might not do every single day, if you had a conscience like Bunyan in Grace Abounding [paragr. 82] tells us his became for a time.

But all this time, as to the act of sinning, I never was so tender as now. I durst not take a pin or a stick, though but so big as a straw, for my conscience now was sore, and would smart at every touch. I could not now tell how to speak my words for fear I should misplace them. Oh! how gingerly did I then go in all I said and did!

Indeed, Bishop Butler (Sermons, ii) was hardly exaggerating when he uttered his famous words about the conscience: “Had it strength as it has right, had it power as it has manifest authority, it would absolutely govern the world.”

And if you don’t think so, ask the family of Admiral Boorda, whose conscience executed him by his own hand. And, for that matter, ask the numerous journalists who, struck by conscience, have either acknowledged their wrong in that whole sad affair, or, at least, felt constrained to justify themselves publicly.

It is precisely because the conscience is an instrument of the divine will, bears witness to God’s own law, precisely because it serves as God’s own voice in the soul, that the conscience has such authority, that the Scripture can even virtually identify it with God.

Think of Peter, in 1 Pet. 2:19, saying that we are to bear up under the pain of unjust suffering because of “conscience toward God” [the NIV changes the ordinary meaning of the word but the weight of argument is against it].

Or Paul (Rom. 13:5) saying, “Therefore it is necessary to submit to the authorities, not only because of possible punishment but also because of conscience.”

And it is because of this authority that we are required to be subject not only to our own consciences, but as well to the consciences of others. The conscience is a faculty so fundamental to the moral life of human beings that it is not to be trifled with, but is to be respected and served, even when it is misguided, overscrupulous, or mistaken.

It is also because of this authority of moral judgment that must be respected that Paul wished, as he says in 2 Cor. 4:2, to act so as “to commend himself to every man’s conscience in the sight of God.”

But, the Bible also recognizes that consciences comes in different shapes and sizes, different moral and spiritual conditions. The Bible speaks of a “good” or “clear” conscience (1 Tim. 1:5,19; Heb. 13:18) by which is meant a conscience that is approving of one’s behavior because it is pleasing to God.

Contrarily, the Bible speaks of a “guilty” conscience (Heb. 10:22), that is a conscience that condemns us for our sin.

But, the Bible also speaks of “weak” or “defiled” or “wounded” consciences (1 Cor. 8:7,12), by which is meant consciences that are over-scrupulous, too easily offended, improperly judging someone’s behavior out of ignorance or sinful biases. The classic cases of such consciences in the NT are those Paul deals with in 1 Cor. 8,10 and Rom. 14.

The Bible even speaks of a “conscience that has been seared as with a hot iron.” This is a conscience that has been rendered powerless and silent. By constantly arguing with their consciences, rebelling against them, stifling the warnings of their consciences such people have at last reached the point where their consciences no longer bother them, no longer even speak to them.

Now, then, let me apply the doctrine of conscience to our living as Christians by summarizing various parts of that doctrine.

1. First, a good conscience is a great advantage in the life of

Some have thought less of a conscience than others, perhaps because it causes so much bother but never has to answer for its mistakes. Mark Twain has one of his characters say that if he had a “yaller dog” that was not worth more than a conscience, he’d take it out and shoot it. [Jones, p. 73]

1. Think of Job, who was prevented from accepting and
acting upon the bad advice of his counselors by his own
good conscience!

2. Or Paul in 2 Cor. 1:12:

“Now this is our boast: Our conscience testifies that we have conducted ourselves in the world, and especially in our relations with you, in the holiness and sincerity that are from God.”

Now, obviously, you must care to have a clear conscience if you are to be able to say such a thing as that. The reason Paul had such a conscience was because he cared to have one (2 Cor. 4:2).

A good conscience is a powerful source of assurance and of the strength that godliness requires in a world of all manner of opposition. An approving conscience is an enormous encouragement to steadfastness. A conscience free to speak and readily obeyed wonderfully clarifies the otherwise murky business of living a holy life in a sinful world.

Think of Martin Luther at Worms replying to those who were threatening him if he would not retract his teachings about justification, etc.:

Unless I am convinced by the testimony of Scriptures or by clear reason…I am bound by the Scriptures I have quoted and my conscience is captive to the Word of God. I cannot and I will not retract anything, since it is neither safe nor right to go against conscience. I cannot do otherwise, here I stand, may God help me. Amen.

A man or woman who knows that he or she has listened to God and done what he required finds tremendous strength and satisfaction and security in that, no matter what the cost of the obedience may have been.

Paul says clearly that a conscience that is clear is a very important instrument in the life of faith and that if a man loves his eternal soul he will want to keep his conscience clear before both God and man. For, if he keeps his conscience clear, he will be living a life of true faith and obedience. So he puts it in Acts 24:15,16:

…I have the same hope in God as these men, that there will be a resurrection of both the righteous and the wicked. So I strive always to keep my conscience clear before God and man.

The reverse side of this duty, of course, is to keep your conscience from being dulled, which protection is given in three ways:

1. First, by not constantly exposing it to sins that would harden
and render insensitive a conscience over time. This is what
makes TV so dangerous, and movies, and books — they make evil
seem commonplace and even so to your conscience. It no longer
thinks to speak to you about what has become so much a part, an
ordinary part of your life. (Not the main reason, but one very
important reason for Christian education in the right kind of
Christian school — protect as much as you can one of your
most precious possessions, an unspoiled conscience that still
offense at impurity, irreverence; still gets sick at violence
against human beings, etc.

2. Second, the conscience is protected by providing it reinforcement in its sound and holy judgments: by reading the
Bible, other Christian works that commend righteousness to you, by commending the righteous behavior of your Christian friends (and being then commended in return for yours).

3. And, third, by obeying your conscience when it speaks; obeying
it as a matter of principle, as unto the Lord. Honor its authority, indeed ask it for more direct rule over you and pray that God would strengthen its reign in your heart and life. And make it, on purpose, the rule of your daily life. When it speaks, sit up, listen, and obey!

2. Second, on the other hand, conscience is not a sovereign, its
voice is that of a minister, not the King himself, and so must
always be subject to and open to correction from the Word of
God itself.

Jiminy Cricket in Pinocchio used to say, “Always let conscience be your guide.” But probably all of us have met people who said of some behavior that we know to be wrong “My conscience is clear.” [Telephone conversation with a homosexual man inquiring about the church.] Paul himself once was conscience bound, as he says in Acts 26:9: “to do all that was possible to oppose the name of Jesus of Nazareth.”

Paul, rather says (1 Cor. 4:4): “My conscience is clear, but that does not make me innocent. It is the Lord who judges me.” In other words, Paul is perfectly well aware that he may be ignorant of some defect in his life or behavior (“forgive my secret sins”) that God knows only too well.

And on the other side, we can condemn ourselves, our consciences can be hard on us, convict us of sins when in fact we are free and clear of any guilt.

Think of John’s statement (1 Jn. 3:19-20): “This then is how we know that we belong to the truth, and how we set our hearts at rest in his presence whenever our hearts condemn us. For God is greater than our hearts, and he knows everything.” In other words, Bunyan’s conscience could still condemn him as a guilty, unforgiven sinner for a year after his coming to faith in Christ, but in this his conscience was mistaken.

In other words, a conscience must not only be kept pure, as we already said, but must be instructed and trained. The conscience must grow up into Christ as every other faculty of the soul. Ignorance, as Paul says in Eph. 4:18, darkens the conscience.

When, in his famous interviews with Mary Queen of Scots, John Knox pressed her on some point and she replied, “My conscience is nott so,” Knox replied in turn, “Conscience, Madam, requyres knowledge; and I fear that rycht knowledge ye have none.”

This, of course, is the subject Paul deals with at length in 1 Cor. 8,10. There were consciences in the Corinthian church that were mistaken in their views of right and wrong in the matter of meat offered to idols. Paul actually deals with another aspect of that matter, but the point is clear. The consciences of these folk were troubling them unnecessarily and mistakenly. Conscience is always subject to the Word of God. We are sinners through and through and our consciences are not unaffected by our sin. To function best a conscience must be thoroughly educated in the Word of God. After all, Paul says the law is written on the heart — meaning the 10 commandments — not all the ethical teaching of the Bible.

Some questions of right and wrong are easily answered; others
require deeper understanding, greater learning. We were discussing at our Sunday table a week ago the question of legalizing drugs. Not so easy a question to answer. Powerful arguments on both sides. What does your conscience say? But what does it know about the large and difficult question of drawing the line between private and public evil?

But, in addition to learning, the conscience needs training, as the author of Hebrews says (5:14): “But solid food is for the mature, who by constant use have trained themselves to distinguish good from evil.”

In other words, those who have seriously practiced their consciences, have put them to work on high and deep matters of righteousness, are likely to find that their consciences are more astute, wise, discerning than those who have left their consciences pretty much where they found them.

What does your conscience tell you about: how slow you are to be to speak? about exactly how to determine what is modest? about exactly how generous you ought to be to someone in need? about when to raise your scruples in the presence of those who do not have them (Prof. Murray with Machen and Prof. and Mrs. O.T. Allis of old Princeton for a Sabbath dinner. Machen and Allis fell to discussing baseball. Mrs. Allis then innocently asked Murray about his opinion of some baseball player and got for her trouble the reply: “I never discuss baseball on the Sabbath.”) But, then, in another instance a little boy brought a decorated Easter egg to Prof. Murray as a present. It was received with thanks and a hug. Some seminarians present, after the little boy had left with his mother, asked him how someone, who was theologically opposed to the observance of any NT religious holidays, could accept an Easter egg of all things? Prof. Murray answered: “Receive all things with thanksgiving, asking no questions for conscience sake.”

Have you trained your conscience, by long exercise, by careful
consideration of your experience, by the investigation of the Word of God, by discussion with spiritually minded friends, and by the life of prayer that seeks to be righteous before God in everything great and small, have you trained your conscience, I say, to know what to tell you in such cases as those and thousands of others like them. When is a person a pig before whom you ought not to cast your pearls? When is it right to stay and fight and when is it right to turn and run? When exactly has my enemy struck me on the cheek that I must turn my other?

This is what Paul is referring to when, in Rom. 9:1, he writes: “I speak the truth in Christ — I am not lying, my conscience confirms it in the Holy Spirit…” The conscience that is a true guide and God’s real voice in our hearts and lives, a conscience that can be relied upon, is a conscience that is being renewed and illumined by the Holy Spirit. That’s the conscience we must have and what a great advantage to have one! God’s own voice speaking in our hearts, telling us what we are to do or not to do.

Alexander Whyte, a loyal Scot if ever there was one, admitted that he always had a problem with the novels of Sir Walter Scott. Scott was Scotland’s greatest writer and most famous novelist, but Whyte could never read those books in peace, could never enjoy them the way everyone else enjoyed them. And the reason was that Alexander Whyte had been brought up, he often said, to love the Covenanters and Scott made fun of the Covenanters in his novels and Whyte’s conscience wouldn’t let him enjoy anything at the expense of those heros of faith that from his boyhood on had taught him what it truly means to love and serve the Lord. Now, whether his conscience was speaking correctly or not, do you not see how differently a man must live who has such a conscience speaking to him, even about what books he can read and enjoy?

What we need in the church is a far larger number of Christians with highly trained, learned consciences who are committed to keeping their consciences clear before God and man, because that is a very good way to ensure that you will live each day as unto the Lord and do much more and refuse to do much more than most Christian men and women ever do or refuse to do.