1 Corinthians 6:12-20
All things are lawful for me, but all things are not helpful. All things are lawful for me, but I will not be brought under the power of any. Foods for the stomach and the stomach for foods, but God will destroy both it and them. Now the body is not for sexual immorality but for the Lord, and the Lord for the body. And God both raised up the Lord and will also raise us up by His power. 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 harlot? Certainly not! Or do you not know that he who is joined to a harlot is one body with her? For “the two,” He says, “shall become one flesh.” But he who is joined to the Lord is one spirit with Him. Flee sexual immorality. Every sin that a man does is outside the body, but he who commits sexual immorality sins against his own body. Or do you not know that your body is the temple of the Holy Spirit who is in you, whom you have from God, and you are not your own? For you were bought at a price; therefore glorify God in your body and in your spirit, which are God’s.
For the fleshly movements that we referred to previously have been placed in our body by the Creator’s providence for a good purpose. They are there for the renewal of the race and for raising up progeny for posterity, not for the perpetuating the disgraces of debauchery and adultery which are condemned even by the authority of law. (John Cassian, The Institutes, 170)