1 Corinthians 6:15, Your Bodies Are Members of Christ
Matthew Poole said well, “Christ is united to the person of the believer, and He is the Head of the church, which is His mystical body; so that the bodies of believers are in a sense the members of Christ, and should be used by us as the members of Christ, which we should not rend from Him: but he that doth commit fornication, rends his body from Christ, and maketh it the member of an harlot; for as the man and wife are one flesh by Divine ordination, Genesis 2:24, so the fornicater and the harlot are one flesh by an impure” union.