1 Corinthians 6:15

Know ye not that your bodies are the members of Christ? shall I then take the members of Christ, and make them the members of an harlot? God forbid.

Believers' bodies are the members of Christ, His purchased property, not their own to use as they please. They become His members because Jesus loved them and provided for blood-bought souls a new birth with new life derived from His own life as the branch derives life from the parent stock, so that they draw motive power and texture of character from Him. Having Christ in them is the test of faith, and being His members defines their position, endowment, accountability and duty, with no life apart from eating the flesh and drinking the blood of the Son of man. The word is spoken to those who claim to be Christians, not to those who have made no profession of righteousness, for those who are subjects of the enemy are not the temples of God.

The verse forbids taking Christ's members and making them the members of a harlot, which means the body must not be joined to sexual immorality. He who is joined to a harlot is one body and one flesh with her, but he who is joined to the Lord is one spirit with Him. Keeping the body from sexual immorality includes avoiding incompatible unions. Fornication here includes letting mind and body be governed by baser passion and indulging lustful practices, too often continued through all the years husband and wife are united, which spoils purity in the home and in other homes, destroys self-control and moral power, debases the mind, weakens the brain and vital forces, and leaves the whole being diseased in body, soul and spirit and debased beyond remedy. Oneness with Christ instead requires sanctification of body, soul and spirit, treating the body as God's property bought with the price of the life of the Son of God and keeping it holy as a fit temple for the indwelling of the Holy Spirit, so that soul and body are in harmony with God.

Because the body belongs to Christ, harming it through perverted appetite and disregard for its laws dishonors God and corrupts the representation of the Maker. That belonging grounds the call to honor God in bodily choices including eating and drinking, devoting the body to God and glorifying God in body and spirit which are God's. The body must not be degraded by sinful indulgence, especially indulgence of appetite by which thousands fall. Those who would have good health must properly appreciate their bodies, understand how to preserve themselves from suffering and disease, and exercise God-given capabilities by striving to overcome temptation. Every person is to do his utmost to keep every organ, every nerve, muscle and sinew in perfect health, to keep the body free from disease by thoughtfulness, self-denial and intelligence. To disregard this, to take little or no pains to preserve health and prevent disease in order to please and gratify self, is to misuse what belongs to Christ.

The verse means the whole person, mind, soul, body and strength, is to be presented to God as a living sacrifice, holy and acceptable, to answer the purpose of creation. For those living in the last days this requires strict temperance and intelligence in eating and drinking, refusing to bring feebleness by wrong habits of diet, refusing to obey bodily lusts, and keeping the body under subjection, because the body is the temple of the Holy Ghost, bought with a price, not one's own. The verse requires making no concessions to the enemy, changing not one principle of truth received from God, and holding no converse with those in league with evil angels, because Christ never purchased peace by compromise. Bodies and souls must not be joined to sin, unbelief and the teachings of the prince of darkness. Ministers and medical missionaries must study the whole sixth chapter of First Corinthians as a lesson for this time. They are to wake up, give the warning message, be healed of the maladies of sin and unbelief, have Satan cast out of the heart, and come to the Lord humbling their defective hearts before Him to receive help. Christ's people belong to Him, so dishonoring one of His saints is dishonoring God.