Flee fornication. Every sin that a man does is outside the body; but he that commits fornication sins against his own body.
All Commentaries on 1 Corinthians 6:18 Go To 1 Corinthians 6
Cyprian of Carthage
AD 258
By necessity, the former by free will: the latter, thinking that it is sufficient for him that he has not sacrificed, has been deceived by an error; the former, a violator of the matrimonial tie of another, or entering a brothel, into the sink and filthy gulf of the common people, has befouled by detestable impurity a sanctified body and God's temple, as says the apostle: "Every sin that a man doeth is without the body, but he that committeth fornication sinneth against his own body.".
Ye are not your own, for ye are bought with a great price. Glorify and bear the Lord in your body."