But he who is joined to the Lord becomes one spirit with him. Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body. – 1 Corinthians 6:17-20 ESV

The Corinthians were not taking their union with Christ seriously. Because of the dualistic approach to life, they seemed to believe that what they did with their bodies really didn’t matter. This led them to look on any sins they committed with their bodies as somehow separated from their spiritual lives. You can see the logic behind their thinking in the phrase, “All things are lawful for me” (1 Corinthians 6:12 ESV). This was a common expression used by the Corinthians to excuse their behavior. And it had led them to commit all kinds of sin with impunity, including sexual sin. The very fact that they had refused to deal with the man in their church who was having sexual relations with his stepmother shows how skewed their thinking had become. But Paul is out to confront and correct their improper views of the body and its relationship with sin.

Paul commands them to “flee from sexual immorality” (1 Corinthians 6:18a ESV). He uses the Greek word, φεύγω (pheugō), which means “seek safety by flight or to escape safely out of danger” (“G5343 – pheugō – Strong’s Greek Lexicon (KJV).” Blue Letter Bible). It is the same word he used when writing to Timothy. “But as for you, O man of God, flee these things. Pursue righteousness, godliness, faith, love, steadfastness, gentleness” (1 Timothy 6:11 ESV). Paul had been warning Timothy about those who have an “unhealthy craving for controversy and for quarrels about words, which produce envy, dissension, slander, evil suspicions, and constant friction among people who are depraved in mind and deprived of the truth, imagining that godliness is a means of gain” (1 Timothy 6:4-5 ESV). Paul warned Timothy to flee from these things. Instead, he was to διώκω (diōkō) righteousness, godliness, faith, love, steadfastness and gentleness. The word Paul used means “to run swiftly in order to catch a person or thing, to run after” (“G1377 – diōkō – Strong’s Greek Lexicon (KJV).” Blue Letter Bible). It is not enough to simply run from something. We must also run to something else. But if the Corinthians would not see sexual sin as wrong and dangerous to their spiritual well-being, they were going to continue in it. That was unacceptable to Paul.

So he attempts to paint a vivid picture of the dangers of sexual sin, by emphasizing that every other sin a person commits is “outside the body,” while sexual immorality is a sin “against” the body. The word he uses is a Greek preposition that is most often translated “into.” There is a physical union that takes place in sexual sin unlike any other sin. There is no doubt that all sin requires the use of my body. In order to lie or slander, the tongue is necessary. In order to steal, the hands and feet must be used. To murder another human being requires the mind to plan it and the body to carry out that plan. And while these sins are no less serious than sexual immorality, Paul’s point is that there is a difference. Sexual immorality is a blatant sin against the body, and that body, Paul stresses “is the temple of the Holy Spirit, who lives in you and was given to you by God” (1 Corinthians 6:19b NLT).

As followers of Christ, we enjoy a mystical, but real union with Him. His Spirit lives within us. We take Him with us wherever we go. Paul told the Colossians, “Christ lives in you. This gives you assurance of sharing his glory” (Colossians 1:27 NLT). And so, there is a sense that when someone commits sexual sin with his or her body, they are dragging Christ into that experience. Paul asks the Corinthians, “don’t you realize that if a man joins himself to a prostitute, he becomes one body with her?” (1 Corinthians 6:16a NLT). There is an intimacy and interconnection established. Which is what led Paul to ask, “Don’t you realize that your bodies are actually parts of Christ? Should a man take his body, which is part of Christ, and join it to a prostitute?” (1 Corinthians 6:15 NLT). And just to clear up any possible confusion, Paul’s provides the correct answer: “Never!”

For Paul, union with Christ was an essential doctrine that needed to be understood and made a part of the believer’s daily life. John Murray wrote that “union with Christ is . . . the central truth of the whole doctrine of salvation. . . . It is not simply a phase of the application of redemption; it underlies every aspect of redemption” (Redemption – Accomplished and Applied, Eerdmans, 1955, pp. 201, 205). We are one with Christ. We share His identity. We are progressively being transformed into His likeness. We not only share in His death and resurrection, and all that those things imply, we share in His righteousness. We have the capacity to live like Christ in this lifetime. The very same power that raised Him from the dead lives within us and is available to us. Paul wrote to the Ephesians, “Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places, even as he chose us in him before the foundation of the world, that we should be holy and blameless before him” (Ephesians 1:3-4 ESV). He went on to emphasize their oneness with Christ:

 In him we have redemption through his blood – vs 7

In him we have obtained an inheritance – vs 11

In him you also … were sealed with the promised Holy Spirit – vs 13

We are in Christ. We are one with Christ. Sexual sin uses the body that belongs to Christ and re-purposes it for immorality. It takes what God has bought with the precious blood of His Son, our body, and uses it for ungodly purposes. And in so doing, we degrade and desecrate the very temple of God. Which is why Paul ends this section with a call to “honor God with you body.” Why? Because “You do not belong to yourself, for God bought you with a high price” (1 Corinthians 6:19-20 NLT). We belong to God – body and soul. Your body is no longer yours to do with as you want. It is the temple of God’s Spirit and is to be used to bring God glory and honor. As Paul reminds us, “give your bodies to God because of all he has done for you. Let them be a living and holy sacrifice–the kind he will find acceptable” (Romans 12:1 NLT).