What does it mean to abstain from sexual immorality (1 Thessalonians 4:3)?

If then we are set to walk in a way pleasing to God, we are plainly told that God’s will is that we walk in practical sanctification that abstains from lust, and holds these human vessels as set apart for honourable uses, and not merely for the gratification of evil passions as with those who know not God.

(Vv. 6-8). Further we are warned lest the flesh, taking advantage of the free and happy intercourse of the Christian circle, is allowed to indulge itself in impurity in our social relations with one another. Any wrong of this character against a brother the Lord will avenge. God has called us unto holiness. To give way, therefore to these gross passions is, not only to sin against one another, but to despise God, and ignore the Holy Spirit who has been given to us.

"Furthermore, then, brethren, we beg you and exhort you in the Lord Jesus, even as ye received from us, how ye ought to walk and please God, even as ye also do walk, that ye would abound still more. For ye know what charges we gave you through the Lord Jesus. For this is the will of God, even your sanctification, that ye should abstain from fornication; that each of you know how to possess his own vessel in sanctification and honor (not in passionate desire, even as the Gentiles who know not God), not overstepping the rights of and wronging his brother in the matter, because the Lord is the avenger of all these things, even as we also told you before, and have fully testified. For God has not called us to uncleanness, but in sanctification. He therefore that (in this) disregards (his brother), disregards, not man, but God, who has also given His Holy Spirit to you" (corrected translation).

Having spoken of being unblamable in holiness at the coming of the Lord he exhorts them to live now in sanctification. The motive is to please God. The believer should constantly in his daily life ask himself this question, "Do I please God?" Exhortation to purity in abstaining from fleshly lusts follows. Fornication, licentiousness in various forms were closely connected with the idolatrous worship from which these Thessalonians had been saved. The lust of the flesh was a part of this former religion, as it is still today among different heathen religions. But why these exhortations? Because they were surrounded by these things on all sides, and because the old nature with its tendencies towards these evils was still present with them, as it is with all true believers. No circumstances or position can make the believer secure against these things, without exercise of conscience and self-judgment, and hence these solemn admonitions from the Lord. Each was to possess his own vessel (his own wife) in sanctification and honor, this would be a safe-guard against the numerous immoralities practised among the heathen. If in this matter any one overstepped the rights of another and thus wronged his brother by committing adultery, the Lord would be the avenger; it would be a complete disregard of God who has not called His people to uncleanness, but unto sanctification, to be separated from all these things. Needful were these exhortations for the Thessalonians as they are still to all of us.

This involves abstaining from fornication. His body is for the Lord, not for corrupt purposes, a vessel to be possessed in separation from evil and in honorable devotion to the Lord. All passionate desire is to be judged and firmly turned from. These things might be prevalent among "the Gentiles which know not God," but the Christian is of a completely different character. The possessing of his vessel applies to all the conduct of the believer, and verse 6 warns against going beyond the bounds of propriety to defraud or oppress one's brother in any matter. In whatever relationships we may be placed we must be careful to respect the proper responsibilities of such relationship. It would, of course, be easier to take advantage of one's brother than of a stranger (cf. 1 Tim. 6:2), but this is sin. "The Lord is the Avenger of all such," and of this they had been warned by Paul beforehand.

Uncleanness is here put in contrast to holiness. It is not only righteousness to which we are called, but holiness, which involves the love of what is good and the hatred of evil. Righteousness does not require such feelings as this, but the believer must be holy as well as righteous. If we should think lightly of unseemly conduct, this is not simply despising men's opinions but despising God Himself who, in the very fact of giving us His Holy Spirit has provided the power to both discern and to refuse uncleanness.

On one thing especially was the apostle urgent, the personal purity of those who bore the name of Jesus; and the more so as the Greeks utterly failed in it. Their habits and their literature, their statesmen and their philosophers, all helped on the evil; their very religion conduced to aggravate the defilement by consecrating that to which depraved nature is itself prone. Few can have any adequate notion of the moral horrors of the heathen world, or of the insensibility of men generally to pollutions so shameless Christ changed all for those who believe in Him, leaving an example that they should follow His steps. "For this is God's will, your sanctification, that ye should abstain from fornication; that each of you know how to possess himself of his own vessel in sanctification and honour, not in passion of lust even as also the Gentiles that know not God, that no man over-reach and wrong his brother in the matter; because the Lord is an avenger of all these things, even as we told you before and fully testified." Holiness, of course, goes far beyond freedom from sensuality. Still to stand clear of that which was everywhere sanctioned in ordinary life was no small thing. Nor is the apostle satisfied with the negative duty of abstinence, but calls on "each of them to know how to possess his own vessel in sanctification and honour," instead of letting it drift loosely into sin and shame, "not in passion of lust, even as the Gentiles also that know not God." Acts 15 is proof positive on scripture testimony of that day, painfully confirmed by the disclosures of Pompeii and Herculaneum, to the moral degradation that pervaded even the most civilized portion of the heathen world. When God is dishonoured, man is reprobate; and God, in forgiving and rescuing from the wrath to come through Christ's death and resurrection, gives also a new life in Christ on which the Holy Spirit acts by the word so as to produce fruits of righteousness by Him to God's glory.

Hence the exhortation further, "that he should not over-reach and wrong his brother in the matter, because the Lord is an avenger in respect of all these things, even as we told you before and fully testified." There is no real ground to introduce a new topic here, confounding with Calvin and others τῳ πρ. with τοῖς πρ., still less to suppose with Koppe τῳ enclitic = τινι, "any," like our own Authorised Version (compare 2 Cor. 7:11). It is the apostle's delicate way of referring to the same uncleanness, especially in married circumstances where the rights of a brother were infringed. This demanded and receives special notice. For as the brotherhood of Christians casts them into free and happy and intimate intercourse, there would be peculiar danger in these very circumstances, lest Satan should tempt where flesh was not kept by faith in the place of death, that love only should act in holy ways with Christ before their eyes. There is perhaps no danger more gravely pressed. They are the ways which bring wrath on the sons of disobedience, and all words which make light of the evil are vain: the Lord avenges all these things, and God will judge the guilty. It is not the true grace of God which spares the strongest and repeated warnings; for God called us not for uncleanness, but in sanctification. It is plain that there is no branching off to commercial dealings, or to dishonesty in the affairs of every-day life. Impurity in the social relations of the saints is the evil still in view: and the conclusion is, "Wherefore then he that disregardeth disregardeth not man but God, that also gave his Holy Spirit unto you." Thus does grace, in calling to a moral duty, rise entirely above the mere weighing of such motives as act on men. It is not that delicate consideration of man is omitted: the apostle begins with the slighting of man in the matter, but he forthwith brings in also the immense yet solemn privilege of the Christian, God's gift of the Holy Spirit. How would impurity affect Him Who dwells in the saints, and makes the body God's temple?

The apostle takes up especially the subject of purity, for the pagan morals were so corrupt that impurity was not even accounted to be sin. It appears strange to us that such an exhortation should have been needful to such lively Christians as the Thessalonians; but we do not make allowance enough for the power of those habits in which persons have been brought up, and which become as it were a part of our nature and of the current of our thoughts, and for the action of two distinct natures under the influence of these, though the allowance or cultivation of one soon deadens the other. But the motives given here show upon what entirely new ground, as regards the commonest morality, Christianity places us. The body was but as a vessel to be used at will for whatever service they chose. They were to possess this vessel, instead of allowing themselves to be carried away by the desires of the flesh; because they knew God. They were not to deceive their brethren in these things, for the Lord would take vengeance. God has called us to holiness: it is with Him that we have to do; and if any one despised his brother, taking advantage of his feebleness of mind to encroach upon his rights in this respect, it would be to despise not man but God, who would Himself remember it, and who has given us His Spirit; and to act thus would be to despise that Spirit, both in one's self and in one's brother in whom He also dwells. He who was wronged in this way was not only the husband of a wife, he was the dwelling-place of the Holy Ghost and ought to be respected as such. On what high ground Christianity places a man, and that in connection with our best affections!

"Further, then, brethren, we beseech and exhort you in the Lord Jesus that, as ye received from us how ye ought to walk and please God, even as also ye do walk,* ye abound still more. For ye know what charges we gave you through the Lord Jesus. For this is [the] will of God†, your sanctification, that ye abstain from fornication; that each of you know how to possess himself of his own vessel in sanctification and honour, not in passion of lust, even as also the Gentiles that know not God; that he should not over-reach and wrong his brother in the matter; because the Lord is an avenger in respect of all these things, even as we told you before and fully testified. For God called us not for uncleanness but in sanctification. Wherefore then he that disregardeth disregardeth not man but God that [also] gave‡ His Holy Spirit unto you" (1 Thess. 4:1-8).

How they "ought to walk and to please God" (4:1) was another thing that Paul taught the converts. The sin of fornication was not regarded as a serious offence in the big heathen cities of the empire. But the Christians were to abstain from it, and to remember that "God has not called us unto uncleanness, but unto holiness" (4:7). To urge purity and practical holiness is a duty that the true pastor will not neglect.

The whole of Scripture is full of the errors of fornication (Acts 15 v 29) and adultery (Exodus 20 v 14). The first is sexual relationship outside of marriage and the second sexual relationship with a married person. We must clearly state that physical affection is only intended by God for one man and one woman and that within the confines of marriage and to a very limited extent by a couple committed to marriage (see previous chapter).

"Marriage is honourable in all and the bed undefiled." Hebrews 13 v 3.

As part of the blessing of marriage God has given us the pleasure of showing love through physical union and the freedom of the display of mutual affection; all within the bounds of a secure relationship.

In the marriage relationship there is complete freedom in this respect but outside marriage this is forbidden as we can clearly see from our scripture. The world does not see this distinction and the holiness and purity that God intended is destroyed. This relaxation of God's standard where physical relationships are entered into wherever and with whoever one chooses, can only bring guilt and misery.

On the other hand, God has expressed His will in His Word as to many things that have to do with our practical, daily lives. Do we rejoice in His expressed will as to what our conduct should be? These things we may know absolutely also, as for instance, "This is the will of God, your sanctification: that you should abstain from sexual immorality." Many other scriptures show us clearly what kind of conduct is right and becoming. Let us be well acquainted with these through reading and meditation.