Or do you not know that he who is joined to a prostitute becomes one body with her? For, as it is written, “The two will become one flesh.” 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 6:16–20
In 1 Corinthians, Paul uses ONE FLESH to show why sexual immorality is so destructive. Corinth was a sexual place. It is clear from Paul’s letter that they had gotten comfortable with sexual immorality. They tolerated it. They even celebrated it. Paul is disgusted by this and calls them to purge this sinfulness from among them.
Sexual immorality means any sexual activity outside of one man and one woman in the marriage relationship. A husband and wife who have been joined together as one flesh should enjoy sex as a physical reflection of the spiritual union God has created.
Sex is a way for married couples to enjoy physical intimacy. To provide for and serve one another sexually. To grow in loving unity. Sex is a powerful part of a healthy marriage.
Sex can also work against intimacy and unity. Sex outside of marriage has the ability to bring sin into a place that is meant to be kept pure. As the author of Hebrews states:
Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous. | Hebrews 13:4
God’s intention was for people to abstain from sex until they are married, keeping themselves pure for their spouse. Once married, husband and wife get to enjoy their unity in a physical way, but must be sure to keep the marriage bed undefiled – by not allowing sexual immorality of any kind to bring shame into it.
As Paul said in the letter to the Corinthians, sexual relations create a link between people. He says: one who is joined to a prostitute becomes one body with her. Sex is not just something that you can walk away from and move on from. Part of who you are remains with that person. Part of who you are is no longer there for your spouse. You are not simply cheating on them, but you are robbing your spouse, and yourself of the deep bond of marriage God created you to have. This is why Paul says that sexual immorality is a sin against your own body.
Paul ends that section by giving us a tool to use against our sinful flesh: remember that your body is a temple of the Holy Spirit. Every time you imagine getting away with some hidden sin, remember that God is with you at all times. Keeping yourself pure is not only a gift to your spouse, and a benefit to you, but it is a way to glorify God with our bodies.
Purity is God’s plan – sex is meant only for husband and wife within the marriage union. That said, we also have a God of redemption. While we should not use grace to justify future sin, we can lean into grace when we have had sex before marriage.
Do not let past mistakes justify additional ones. Instead, choose this day to pursue sexual purity in your marriage by turning away from all other temptations toward your spouse.