“Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.”
King James Version (KJV)
6:18 Flee fornication - All unlawful commerce with women, with speed, with abhorrence, with all your might. Every sin that a man commits against his neighbour terminates upon an object out of himself, and does not so immediately pollute his body, though it does his soul. But he that committeth fornication, sinneth against his own body - Pollutes, dishonours, and degrades it to a level with brute beasts.
1Co 6:18 Flee fornication. The sin must be fled. The way to avoid it is to avoid temptation. We must conquer by running away. Thus it was that Joseph prevailed. Every sin that a man doeth is without the body. The temptations come from without and assail the man through the sense. This is the rule in the case of sin. But he that committeth fornication sinneth against his own body. It is not said of fornication that it is not stimulated without, or that it, alone of sins, assails the body, but that it is peculiarly a sin against the body. It defiles a body which is designed to be a member of Christ, and a temple of the Holy Spirit; separates it from the union with Christ, and unites it with a harlot. The grievousness of the sin is in the desecration to such an unholy purpose of a body which has become a member of Christ, a part of the temple of God.