First Corinthians 6.15-18


1. This evening's message is the second of three messages that I have grouped together under the single title "Carnality's Ignorance."

2. The specific reason I chose the title, "Carnality's Ignorance," stems from a phrase Paul uses four times between 6.9 and 6.20 of First Corinthians. In verse 9, Paul writes, "Know ye not . . . ?" In verse 15, Paul begins, "Know ye not . . . ?" In verse 16, Paul continues, "What? know ye not . . . ?" And finally, in verse 19, Paul asks one last time, "What? know ye not . . . ?"

3. Apparently, there are some truths which carnal Christians simply do not fully appreciate, if they appreciate them at all. Apparently, sin in the life of the child of God, sin which is not dealt with in a Biblical way, can severely cloud the vision, can severely impair the spiritual eyesight, can severely distort the believer's perception of reality. This is what happened to the Corinthians during their brief but rapid slide into carnality.

4. As a matter of fact, such distortion of reality and impairment of perception can result in a believer acting much like a lost person in many ways during such periods of carnal indulgence. Let me give you an example of the perceptions and the behavior of both lost and carnal people:

5. When confronted with the harmful effects of violence and immorality on television and videos, folks will vehemently deny that watching someone brutally raped or murdered, or watching pugnacious rebels defy authority figures, or watching one human being beat the stuffings out of another human being, has any effect on people's sensitivities, sensibilities, or behavior.

6. But, when you think about it, is not the entire Madison Avenue advertising industry based on what changes in behavior you can effect with only 30 or 60 seconds of exposure to a carefully thought out message? Of course it is. And of course violence, immorality, and rebellion harms those who see it glorified. Anyone who listens to news reports of how teens act when they come out of movie houses, raping, beating, murdering, just like they saw in the movie, can see this. But watching illicit sex scenes at a movie or on a video, has no effect on anyone? Come on. And you guys who like to watch boxing need to take a serious and objective look at what you are doing. No doubt it's enjoyable. But that's not the issue, is it?

7. The child of God, unlike the unregenerate, needs none of the reasoning I've just presented. Why not? Because Psalm 101.3 reads, "I will set no wicked thing before mine eyes." Being very careful of what he watches, reads, or listens to, the spiritual Christian is simply not programmed or tempted like the lost person is to do such things. Why? He vigorously opposes the world's attempts to propagandize his thinking.

8. Now, this is all fine and good, except when the carnal Christian is considered. The carnal Christian muddies the water terribly. On one hand, he or she is heaven-bound, having trusted Christ as personal Savior. But on the other hand, the carnal believer's behavior approximates the behavior and the thinking patterns of a lost person; at least during that period of time when he's carnal.

9. And as a lost person is profoundly ignorant of certain spiritual realities, so the carnal believer, behaving as he does so much like a lost person in some ways, is also profoundly ignorant of certain truths.

10. You may remember several weeks ago, in our study of First Corinthians 6.9-14, that the carnal Christian is ignorant of certain distinctions. Those Corinthians, and carnal believers today, did not realize that certain sins broadcast the destiny of the person who habitually commits them, #1, and that, as Christians, such behavior is supposed to be in our past, not our present, #2. Of those two distinctions carnal Christians are ignorant.

11. In today's text we look at a second area of profound ignorance. Carnal Christians simply do not know, or understand, or realize, the damage caused by sin.

12. This is true as a general rule. But to cite a specific example of this general truth, Paul deals with the specific sin of fornication. Let's stand as we read First Corinthians 6.15-18: "Know ye not that your bodies are the members of Christ? shall I then take the members of Christ, and make them the members of an harlot? God forbid. What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh. But he that is joined unto the Lord is one spirit. Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body."

13. Three statements help us to understand the seriousness of this sin, and perhaps convince the carnal Christian, who can be severely tempted to commit this sin, to stay as far away from it as possible.


"Know ye not that your bodies are the members of Christ? shall I then take the members of Christ, and make them the members of an harlot? God forbid."

1B. Notice The Manner By Which Paul Communicates This Principle

1C. He uses rhetorical questions. A rhetorical question is a question that you ask, not to discover the answer, but to make a point. Why? Because the answer to the question is obvious.

2C. Notice the two questions he asks in this verse. The first question, "Know ye not that your bodies are members of Christ?" addresses the problem of ignorance. Of course, they intellectually know that their bodies are members of Christ. But had they a heart knowledge of such profound truth they never would have committed the sins they had engaged in, or tolerated this particular sin by someone in their Church.

3C. Question #2 addresses their behavior. "Shall I then take the members of Christ, and make them the members of an harlot?" When you put it that way, "Of course not!" You see, you don't usually get the right answers until you ask the right questions. Amen? Or until you ask the question the right way. 

4C. Is a relationship wrong? That's one way of asking a question, loading it with euphemism to cloud the issue. But when you ask if copulating with a whore is wrong, the answer is obviously "No!"

5C. "Pastor, you are being unduly blunt and rude." Am I? Look at the word "take." A. T. Robertson points out that the Greek word this translates is the word that "rape" comes from. Paul was indicating that when you commit fornication you are actually violating something which is a member of Christ . . . the body you inhabit. 

2B. Now Notice The Meaning Paul Seeks To Communicate By This Principle

1C. You, and you, and you, and you, and you. Are you a Christian? Have you trusted Jesus Christ to the saving of your soul?

2C. Then, in the most profound sense, there is a genuine unity that exists between your body and the Lord Jesus Christ. Your body is actually a member of Christ.

3C. How horrible, then, to take that which is one with Christ and join it together and make it one with an harlot.

4C. "But she isn't a harlot. She's my girlfriend." Oh? A harlot sells sex for money or some other consideration. Will your friend give you sex if you stop driving her around in your car, if you stop feeding her, if you stop buying her things, if you stop bribing her with the kind of affection and intimacy that is due only a wife? I think not. She's a harlot after all.

5C. And what about the man? Is he any better? Absolutely not. He who procures the favors of a harlot is one of the lowest forms of life. Amen? The Bible calls such a man a whoremonger.

6C. The principle of the believer's body being a member of Christ is not understood by the carnal believer, though this truth dominates on a daily basis the lifestyle of the spiritual child of God.


"What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh. But he that is joined unto the Lord is one spirit."

Here Paul attempts to show that fornication by a Christian is unthinkable. Why is it unthinkable? It's unthinkable because:

1B. During Sexual Intercourse The Believer And The Harlot Become One Flesh

1C. We see this truth in the last phrase of verse 15 and verse 16.

2C. Folks, the joining together of a believer and an harlot in one flesh is a gross violation of God's plan for marriage, for meeting of legitimate sexual needs, for presenting marriage as a picture of the believer's union with Christ. You see, God's plan is one mate, one union, for life.

3C. And the portion for those who violate God's plan is serious indeed. The consequences of such sin as this can be seen in three areas:

1D. First, there are physical consequences. Can a virgin who marries a virgin get any venereal disease, so long as the two of them are faithful to their marriage covenant? No. Would diseases such as AIDS, herpes, syphilis, gonorrhea, or others, continue to exist without the sin of fornication? Of course not. In a generation they would all disappear. Yet those whose thoughts are controlled by their glands will keep right on fornicating, won't they? Even if it's a Christian who's temporarily controlled by his or her glands.

2D. Next, there are emotional consequences. The various ways in which fornication can impact a life and a marriage emotionally are legion, but allow me to raise just two notions to consider.

1E. First, there is the matter of respect. Realizing the critical role that respect plays in a marriage, how in the world can a husband or wife respect their mate as much as they might have had fornication not entered into the picture? How do you respect someone who has a demonstrated tendency to be a taker rather than a giver, a luster rather than a lover, a user rather than one who seeks to build those around him or her? And how in the world do you establish respect for someone who exposes himself to death for a few moment's satisfaction of an urge?

2E. Then there is the matter of memory. Let's say your mate isn't aware of your fornication before marriage, or your adultery during marriage, for that matter. But you are aware of it. You have memory of that act of sin committed with someone youthful and energetic and attractive. What a curse. You will forever be cursed with the memories of sexual sin with someone young, while you and your mate grow old. Do you think those memories will enhance your marriage? Do you think it will make you a better lover to your spouse to have another in your mind who is younger, more passionate, than your mate will be in later years? I don't think so. I am of the opinion that the emotional consequences of this sin are much more crippling to a person and to a marriage than most of us will ever realize.

3D. Finally, there is the spiritual consequence of fornication. Folks, the subject of unity has been a major theme in this letter from Paul. He urges certain kinds of behavior based upon the unity that does exist between the believer and Christ and between the believer and his brothers and sisters. But what damage is done to that spirit of unity, that oneness, when a person who possesses spiritual unity with Christ also establishes a physical unity with someone who stands against everything the cause of Christ stands for? 

4D. Will there be grief in your spirit? Will there be obstacles to the Holy Spirit's ministry in your life? Will there be destruction of one's testimony among both the saved and the lost? To be sure. Is that of any concern to the fornicating carnal Christian? Not at the time of the sin, to be sure. Otherwise he wouldn't be carnal. But someday it will be of concern to him, or to her. Someday there will be great sorrow.

5D. Do not commit fornication, in part, because when you do you become one flesh with the harlot you are joined to.

2B. The Second Reason Why Committing Fornication Is Unthinkable For The Christian Is Because The Believer And Christ Are One Spirit (17)

"But he that is joined unto the Lord is one spirit."

1C. Turn to John 17.20-23 and read: "Neither pray I for these alone, but for them also which shall believe on me through their word; That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me. And the glory which thou gavest me I have given them; that they may be one, even as we are one: I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou hast loved me."

2C. Here we see the passion of our Lord Jesus Christ for unity among the brethren. And the unity we are to have springs from the unity that each of us has with our Lord. And one of the benefits of this unity? Evangelism. The world believing that the Jesus we preach is sent from God.

3C. Now turn to Second Peter 1.2-4: "Grace and peace be multiplied unto you through the knowledge of God, and of Jesus our Lord, According as his divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue: Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust." 

4C. The word "partaker" refers to sharing something with another. We share God's very nature with Him when we become His children by the new birth. And the word "lust." Is not this what fornication springs from, lust? Sure it is. But the Christian is supposedly liberated from the corruption that is in the world through lust.

5C. Do you see why the child of God, the genuine Christian, must do everything he or she can to avoid committing such a sin as this? Fornication is a most profound contradiction to the spirit of unity that does exist between Christians and Christ and between Christians and Christians. For a Christian to commit fornication is a hypocrisy of the first magnitude. For these two reasons, the believer and the harlot become one flesh during fornication, and the believer and Christ are one spirit always, fornication is prohibited.

6C. My friend, no step you take is too extreme in seeking to avoid committing sin, especially the sins of fornication and adultery. And if you have had even a near miss once, and you don't take extreme measures to avoid this sin in the future, then you are probably making provision for the flesh to actually commit this sin.


Propriety has to do with that which is proper, fitting, suitable. I want us to see what propriety dictates when faced with the temptation to commit fornication.

"Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body."

1B. There Is The Response To Danger . . . Flee

1C. Folks, this word "flee" carries the idea of abruptness. When tempted in this manner do not try to hold out, do not try to resist, do not try to be noble. What you do is run.

2C. Of course, the best thing to do is to not make provision for the flesh. A young man who is courting should always keep a young lady's company in public, around parents, or in group. I would advise against single couple dating in any form, at any time, regardless of the age of the couple. "But why, pastor?" Because you are one with Christ, that's why? Or are you?

3C. But should the opportunity present itself inadvertently, should the temptation arise, run. Care not for what others think of you. Have no concern for good manners. Run. What are the opinions of others and good manners next to the possibility of a ruined life or a destroyed marriage? Run.

4C. It never hurt anyone to run from sin, but many have fallen who did not run. It never harmed a marriage to flee fornication, but many a marriage has been ruined by those who waited to put on their track shoes when they should have fled with what shoes they had on.

5C. The proper response to great spiritual danger is not to pretend it isn't dangerous, and it's not to be so proud as to think you are immune. The proper response to danger is to behave as though it is, indeed, dangerous.

6C. Firemen who live fear fire. Policemen who live fear criminals. Christians who stand are Christians who fear the temptation to commit fornication enough to flee from it.

2B. The Reason Is The Damage

1C. There is no need to fear that which is harmless. But fornication is not harmless.

2C. As Paul states it, every other sin which a person can commit is somehow external to the body, upon the body. But there is a sense in which fornication is truly an inner sin.

3C. Is it because fornication joins you with one who is an harlot in a physical unity that mocks your spiritual unity with Christ? Perhaps.

4C. Is it because fornication is a terrible distortion and perversion of the ideal, which is sex in marriage, not sex outside of marriage? Perhaps.

5C. Is it because fornication is a supremely selfish act, while the Christian life, a reflection of the Lord Jesus, is diametrically opposed to the selfishness of lust? Perhaps.

6C. Whatever the reason, precisely, Paul points out that sexual sin affects the Christian's life and the Christian's body in a way much more serious than any other kind of sin.


1. Have you ever examined the Bible to discover the ways in which God instructs His children to deal with the various temptations to commit sin?

2. When tempted to think improper thoughts, do this. When tempted to say that, do this. When contemplating retaliation in this way, do this instead. 

3. If I recall correctly, each of the various temptations that we face is to be resisted or deflected in a specific way that is found in the Bible, except for two.

4. The temptations to commit only two sins are to be handled in a particular way, and that way is to flee. Flee idolatry and flee fornication.

5. We know the hatred that our God has for idolatry. In Old Testament times the idolater was to be stoned to death, lest his false beliefs infect the whole nation. 

6. So, rather than deal with that temptation, God directed people to run from it. And the same thing is true of fornication. Flee.

7. Just seeing how God wants us to react to the temptation should tell us how dangerous God sees fornication to be to us, our lives, our testimonies.

8. But carnal Christians minimize the danger of fornication. They are oblivious to the damage it causes in the lives of the ones who commit the sin, the damage to the families affected, the Churches which may be impacted by the sin, etc.

9. Not that every carnal Christian will commit fornication, because they certainly will not. Most "Christians" who commit fornication are likely lost. But many carnal Christians will observe it, will be aware of it, and will do nothing to stop it in their midst. That's what was happening in Corinth.

10. Because they are unaware of the damage it causes, they will not confront their friends who are fornicators, they will not rebuke their acquaintances who are fornicators. And finally, they will not open God's Word to Matthew chapter 18 and insist that those who claim to be Christians who are doing it stop destroying themselves and others who are around them.

11. When Paul addressed the fornication in First Corinthians chapter 5, did he speak to the fornicator or those who were aware of it? Those who were aware of it. And as he writes here, does he address the believer who thinks only with his or her glands, or is he also addressing those who do not commit fornication but who do not stop it, either?

12. Are you so carnal that you do not see the damage caused by sins? Or are you so carnal that you see and know of brothers or sisters in Christ who are inching their way toward destroying themselves with sin, perhaps even fornication, and you are too timid to obey God in the matter?

13. Friends, listen to God's Word on this matter. Realize what great damage sin, any sin, causes in a person's life and repent. Repent of your carnality, of your paralysis, and realize the damage sin causes. Now, go do something about it.

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