18 Flee sexual immorality. Every sin that a man does is outside the body, but he who commits sexual immorality sins against his own body. 19 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? 20 For you were bought at a price; therefore glorify God in your body and in your spirit, which are God’s. (1 Corinthians 6:18–20, NKJV)
We must run away from sexual immorality. Paul used the general term porneia (fornication) that includes all sinful sexual joining of males and females (1 Cor. 6:15-16). Sexual immorality applies to the sins of premarital, extramarital, and multi-marital sex, homosexuality, incest, and unlawful remarriages (1 Cor. 6:9; Heb. 13:4; Matt. 19:9; Rom. 7:2-3). Every sin we commit begins in the heart (“outside the body,” v. 18), including sexual immorality (Matt. 15:19). Additionally, the sin of fornication violates the purpose of the body (v. 18). Our fellowship with the Holy Spirit necessitates that we use our bodies to glorify God (v. 19). Our bodies are to be living sacrifices to the Lord, offered in holy service to Him instead of being used to indulge the lusts of the flesh (Rom. 12:1-2; 1 Thess. 4:3-5). We were redeemed from sin by the lifeblood of Jesus Christ (1 Pet. 1:18-19). We belong to Him, body, and soul. These are the reasons why Christians must flee sexual immorality: 1) This sin is against the holy purpose given the body, 2) This sin defiles the dwelling place of the Spirit of God, and 3) This sin dishonors God and those who practice it.