1 Corinthians 6:18
Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body. Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.
Fleeing fornication means turning away at once from the first step of wrongdoing without pausing a moment to reason or argue with temptation. The body is not one's own but Christ's purchased property, joined to Christ as His member and to the Lord as one spirit, and the temple of the Holy Spirit, so body and spirit which are God's because bought with a price must be used to glorify God and not as one pleases. To commit fornication is to sin against one's own body by polluting, dishonoring, defiling and debasing it, a heinous sin and serious danger that leads away from God and must never be treated as light or trivial. He who does so remains a subject of the enemy and is no temple of God, so there must be no concessions to the enemy and no purchased peace by compromise. Glorifying God in body and spirit requires refusing to let sin reign in the mortal body by obeying its lusts, but yielding to God as those alive from the dead and yielding the members as instruments of righteousness unto God.
Words and Historical Setting
Corinth was given to the worship of Venus, and its temple prostitution forms the historical setting for the warning to the Corinthians against sexual immorality as sin against one's own body. The command to flee fornication is addressed to those who claim to be Christians and profess righteousness, not to those who have made no profession. It belongs to the lesson of the whole sixth chapter of First Corinthians, which ministers and medical missionaries must study.
The verse wakes up the watchmen to give the warning message for this time. It shows the need to be healed of the maladies of sin and unbelief, to refuse the teachings of the prince of darkness, and to have Satan cast out of the heart. It calls for coming to the Lord, humbling poor, defective hearts before Him to receive help.
To sin against one's own body means that fornication pollutes, dishonors, defiles and debases the body. It is a heinous sin and a serious danger that can lead people away from God. It must not be treated as light or trivial.
Body Belongs to God
Sexual immorality must be fled because it is sin against one's own body, and that body is joined to Christ as a member of Christ and joined to the Lord as one spirit in the covenant of grace. The body is not one's own but Christ's purchased property and the temple of the Holy Spirit, which believers have of God, for they are bought with a price. Therefore body and spirit, which are God's because bought with a price, must be used to glorify God and not as one pleases, so that sexual sin dishonors what belongs to God.
He who commits fornication sins against his own body and remains a subject of the enemy, and no such subject of the enemy is a temple of God. The command to flee is spoken to those who claim to be Christians and profess righteousness, not to those who have made no profession. It therefore requires making no concessions to the enemy, changing not one principle of received truth, holding no converse with those in league with evil angels, and never seeking to purchase peace by compromise, for Christ never purchased peace by compromise.
To sin against one's own body is to dishonor God, because the laws of nature are the laws of God and there is duty to study their requirements for the body and conform to them, and ignorance of them is sin. To treat the body as if its laws have no penalty, and to enfeeble, disease, and cripple its organs and powers through perverted appetite, is to sin against the body and corrupt one's ways. Such corruption makes man an unsightly representation of his Maker, which Satan uses to taunt God.
Seeking pleasures that separate the affections from God is sin against one's own body as well as against God. Secret impure action corrupts a person's own body, and it is done in the presence of the heavenly Father, who is far more exalted, holy and pure than an earthly father, and in the presence of Christ and the pure, sinless angels. The body and its faculties are God's gifts, and pure enjoyment does not debase them.
Glorifying God in body and in spirit which are God's requires heeding God's warning to preserve health and refusing to encourage and educate wrong appetites indulged at the expense of health. It requires becoming intelligent about eating and drinking and about one's own bodily habitation even while living where light is shining. It requires not letting sin reign in mortal bodies by obeying it in the lusts thereof, but yielding to God as those alive from the dead and yielding members as instruments of righteousness unto God.
Fleeing Without Compromise
Fleeing means acting at once and instantly, turning away from the first step of wrongdoing without pausing for a moment to reason or argue with temptation or a weak conscience, because Satan rejoices to overthrow by temptation. The wise follow the example of Joseph in fleeing, controlling appetite and passion and drawing nigh to God to prepare mind and body to discharge aright the duties of life. The lower passions must be strictly guarded and governed rather than allowed to run riot and govern.
Indulging the passions harms the body and can bring disease. It abuses the perceptive faculties, calls blood in undue amount to the internal organs instead of circulating to relieve the heart and clear the mind, and keeps the mind from being healthy until the evil is seen and remedied. Familiar mingling of boys and girls leads youth to sin against their own bodies through sexual vice, with vice stamped upon their features. Fleeing therefore requires keeping the sexes from free association, restraining immodest advances and familiarity, and keeping boys and girls employed in useful labor, for when tired they have less inclination to corrupt their own bodies.
Becoming prudent, modest and virtuous requires earnest effort by watching, praying, meditating, and closely investigating and analyzing motives, feelings, actions and acts. Continuing in self-corruption irrespective of conscience and irrespective of light and warnings given stands condemned. Fornication and adultery cannot be treated lightly or excused while a person continues in them, even while doing religious work, and genuine conversion requires recognizing the sin and turning from it. Forbearance toward those who commit them can lead them to treat the sin as trivial even while their conduct reveals they are impure and unholy.