1 Corinthians 6:15-17

Don’t you know that your bodies belong to Christ as his body parts? Should one presume to take the members of Christ’s body and make them into members of a harlot? Absolutely not! Aren’t you aware of the fact that when anyone sleeps with a prostitute he becomes a part of her, and she becomes a part of him? For it has been declared: The two become a single body. But the one who joins himself to the Lord is mingled into one spirit with him.