15 Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and make them members of a prostitute? Never! 16 Or do you not know that he who is joined[1] to a prostitute becomes one body with her? For, as it is written, "The two will become one flesh." 17 But he who is joined to the Lord becomes one spirit with him. 18 Flee from sexual immorality. Every other sin[2] a person commits is outside the body, but the sexually immoral person sins against his own body.
Matthew Henry's Commentary on 1 Corinthians 6:15-18
Commentary on 1 Corinthians 6:12-20
(Read 1 Corinthians 6:12-20)
Some among the Corinthians seem to have been ready to say, All things are lawful for me. This dangerous conceit St. Paul opposes. There is a liberty wherewith Christ has made us free, in which we must stand fast. But surely a Christian would never put himself into the power of any bodily appetite. The body is for the Lord; is to be an instrument of righteousness to holiness, therefore is never to be made an instrument of sin. It is an honour to the body, that Jesus Christ was raised from the dead; and it will be an honour to our bodies, that they will be raised. The hope of a resurrection to glory, should keep Christians from dishonouring their bodies by fleshly lusts. And if the soul be united to Christ by faith, the whole man is become a member of his spiritual body. Other vices may be conquered in fight; that here cautioned against, only by flight. And vast multitudes are cut off by this vice in its various forms and consequences. Its effects fall not only directly upon the body, but often upon the mind. Our bodies have been redeemed from deserved condemnation and hopeless slavery by the atoning sacrifice of Christ. We are to be clean, as vessels fitted for our Master's use. Being united to Christ as one spirit, and bought with a price of unspeakable value, the believer should consider himself as wholly the Lord's, by the strongest ties. May we make it our business, to the latest day and hour of our lives, to glorify God with our bodies, and with our spirits which are his.