What is a sin outside the body (1 Corinthians 6:18)?

It is not merely that our spirits go to be with the Lord in heaven; our bodies shall be raised like His at His coming, as many bodies of the saints which slept arose and came out of their graves after His resurrection. For if death shows man's weakness, resurrection displays God's power. The actual spiritual effect of this is immense. Not our souls but our bodies are declared to be members of Christ. Those who descant on the soul only may claim a superior elevation. But it is never really so in practice or in theory. On the contrary the immortality of the soul is easily perverted to man's pride; not so the resurrection, which not only exalts God and humbles man but delivers from present ease and indulgence where it is held in faith. Of this the Holy Spirit is the earnest, who joins us to the Lord and constitutes our bodies members of Christ. Hence the enormity of fornication. (Vers. 15, 16.) How basely inconsistent with such intimacy, yea union, is impurity with a harlot! It was the more needful to urge this on a city more than any other noted for this sort of licence, besides the broad fact that the heathen in general regarded fornication as an indifferent act like eating and not as in itself a sin. "The two, says he, shall be one flesh; but he that is joined to the Lord is one Spirit." (Vers. 16, 17.)

But its incongruity with our relation to Christ is not all that the apostle urges. Fornication he would have avoided earnestly, because of its peculiar character, differing as it does from every other sin in this that it is against the body itself, while others are external to it. How dreadful then to think not merely of the body so misused, but the Christian's body, temple of the Holy Spirit as it is! not from any mere consecration to Him but from His being in us, and this from God, on the ground of purchase by Christ's blood. Therefore the apostle's appeal to glorify God in their body.

Verse 18. "Flee fornication," etc. Instead of being regarded as a thing indifferent, or even as a trivial offence, this sin is to be dreaded and shunned as a leprosy; for it contaminates both soul and body. Other sins did so but in part; but this completely, by turning that which God has claimed for Himself to an use which He condemns. A wrong is thus inflicted on the body itself, by alienating it from its true honour as an instrument of righteous worship, and again degrading it to the service of sin. It is, therefore, morally, what idolatry is spiritually; and the dissuasive from both is expressed by the apostle in the same terms.8 Each sin is to be fled from, by those who would please God. But there is a further and especial sense in which a believer's body is said to be sinned against by such an act. And this also the Corinthians should have known.

Verse 19. "What? know ye not that your body is the temple of the Holy Ghost?" There is such a thing as spiritual self-respect. A Christian is expected to forget his first parentage in the remembrance of the second. He is not God's creature only, but His child. As the Son of God became incarnate, to put Himself within reach of our sins, so the believer, who adds knowledge to his faith, should understand that his mortal body is the temple of the Holy Ghost. Sent down by the Father in the name of Jesus, He occupies this earthly house as a pledge and witness of its coming change.9 Now it is God's Spirit which we have of Him, and God's Spirit is His own essential presence. But what God dwells in is His temple. We have in this verse a distributive repetition of the doctrine already stated in an earlier chapter.1 Each Christian body is a temple of the Spirit, even as the collective assembly of saints is His temple, and the place where His honour dwells, in what locality soever that assembly is found. Now what God occupies is His, and not our own. We are not robbed of our natural ownership, but it merges in the higher honour of our calling. Our bodies are His temple — ours, therefore, only as ourselves are His; to be kept then, in sanctification and honour, in His Name.2 Thus a double duty is imposed on the Christian with respect to his own body. He is to manage and govern it with vigilance and godly decision, as a restive and unruly beast; he is to hold it in honour, and tremble to abuse it, because it is the temple of the living God. Are we Christians, and yet ignorant of these things? Once more, then, let the cross be our monitor and shame.

"Flee fornication." In this one is not told to fight, but to keep far from it, as Joseph fled from the wife of Potiphar. Other sins may not involve the body in this way, but this is sin against one's own body. And as well as our bodies being the members of Christ, now we are told, "Your body is the temple of the Holy Ghost." The Spirit of God dwells within our body in order to display in us the precious reality of His character in our practical lives. Notice that it is not said that our spirits or souls are His temple, but our bodies. So that when we are told, "Ye are not your own," we cannot regard this as being merely in regard to our spiritual interests, but fully applicable to our bodies. Being bought with a price - a price so infinitely great - certainly we are totally the property of the Living God; and it is only right and becoming that we should glorify God in our body.

The apostle turns next to fleshly abuses: the first in respect of meats, the second and gravest in fornication. He had shown that, whatever the grace of God is in calling the vilest, all such are saved after a holy sort. This he now exemplifies in two instances where some pleaded liberty to deny practical purity. Of this he will not hear. He will not diminish liberty one jot, but he asserts its character to be Christian, as all our other privileges are. If not of Christ, it is sin. So is it with all we boast: life, righteousness, peace, and glory. In this liberty differs not from the rest. What Christian could wish any of these in or for the flesh? It would be to abandon the Second man for the first: to wish licence for sin proves utter lack of love and honour for the Saviour.

"All things are lawful to me, but all things do not profit; all things are lawful to me, but I will not be brought under the power of any. Meats for the belly, and the belly for meats, but God will bring to nought both it and them; but the body [is] not for fornication but for the Lord, and the Lord for the body. And God both raised the Lord, and will raise up us by his power. Know ye not, that your bodies are members of Christ? Shall I then taking the members of Christ make [them] members of a harlot? Let it not be. What! Know ye not that he that is joined to the harlot is one body? For, says he, the two [shall be] one flesh. But he that is joined to the Lord is one spirit. Flee fornication. Every sin which a man may practise is outside the body, but the fornicator sins against his own body. What! Know ye not that your body† is a temple of the Holy Spirit that [is] in you, which ye have from God; and ye are not your own? For ye were bought with a price: do then glorify God in your body."‡ (Ver. 12-20.)

One more reference to scripture I would make in consequence of having heard it said, "Why do you make more of this sin than of any other?" An awful word! But the apostle says, "Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body. What! know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? for ye are bought with a price: therefore glorify God in your body [and in your spirit, which are God's]" (1 Cor. 6:18-20).

By all things lawful, not all expedient (v. 12), he means that there is no difference to him, but he will not allow anything to have power over him. The moment it governs, lust has power over him if it is only eating something nice. There are a number of details here next: meats for the belly, and the body not for fornication but for the Lord; also the Lord for the body. He has taken up the body as well as the soul, though He has not yet redeemed it out of its present state. It is for the Lord therefore and not for its own lusts. And what the Lord has done is, He has made it the temple of the Holy Ghost. It awaits its redemption in the sense of taking it into glory; my soul has the liberty of grace, and my body waits for the liberty of the glory, and all creation waits. Yet the body now belongs to the Lord, and He takes it for Himself, and the Holy Ghost dwells in it as a temple. "And in your spirits which are God's" in the last verse is a clause left out in all the best manuscripts.

But the doctrine that the body is for Christ decided another question, to which the depraved habits of the Corinthians gave rise. All fornication is forbidden. To us, with our present Christian habits of mind, it is a thing of course — to Pagans, new; but the doctrine exalts every subject. Our bodies are the members of Christ. Another truth connected with this is of great importance: if (by union according to the flesh) two were one body, he who is united to the Lord is one spirit. The Spirit whose fulness is in Christ is the same Spirit who dwells in me and unites me to Him. Our bodies are His temples. What a mighty truth when we think of it!

Then, His way for us is always one in which we are made to realize weakness. Our prayer can never be, "Lead us into temptation," and therefore we are never to act as if this were our prayer. In all cases where escape is possible without disloyalty, we are to flee rather than face it. "Flee also youthful lusts." "Abstain (hold off) from fleshly lusts." Flee, as Joseph fled; and there was, perhaps, no bolder man.

The Apostle then passes on to speak of that which is not lawful for the body — actual sin. Here we are reminded that the body is for the Lord, and the Lord for the body. He reminds us, too, that these bodies are destined for high honour, for even as God has raised up the Lord, so will He also raise up these bodies by His own power. Moreover, our bodies are members of Christ, and he that is joined to the Lord is one Spirit. The Apostle learnt something of this great truth at his conversion, for the Lord said to him, “Why persecutest thou Me?”. To touch the bodies of the saints was to touch Christ. How solemn is all sin, but how specially solemn is sin against the body which is indwelt by the Holy Spirit and belongs to God, and which it is our privilege and responsibility to use for the glory of God. To press upon us the deep importance of holiness, the Apostle reminds us in the course of the chapter that we are washed, sanctified and justified, and further, that our bodies are for the Lord, joined to the Lord, indwelt by the Holy Spirit, belong to God, and are to be used for the glory of God; and, too, the Lord is for the body, and God will raise it up by His power.

This introduces the abuse of liberty. It is not Christian to be under the power of anything. Even now the body is for the Lord; and as God raised Him up from the dead, so will He raise us. We shall be conformed to Him in that glorious change, and are to act now in faith of it. Our bodies are Christ's members. How shameful and disloyal to be joined to a harlot! For this was the habit, one might say the religion, of the old Corinthian community. Hence the enormity of fornication in a saint, who is "one spirit with the Lord." Our body is the temple of the Holy Spirit Who is in us, and this of God. We are not our own, but bought with a price, and therefore to glorify God in our body. The rest of the verse in the Authorised Version and others is a spurious addition from bad manuscripts.