What does the Bible say about sexual immorality?

WHAT DOES THE BIBLE SAY?

The Bible teaches that sexual intimacy is designed by God to be enjoyed within the covenant of marriage between one man and one woman (Genesis 2:24), and any sexual activity outside of that design is defined as sexual immorality. From the beginning, God established clear boundaries for sexual behavior, warning against practices that distort His intent for human relationships (Leviticus 18:20–23). Jesus affirmed that sexual sin is not just behavioral but flows from the heart and must be taken seriously (Matthew 15:19). We must therefore flee all sexual immorality, glorifying God with our bodies, and recognizing that our lives must reflect our identity as those who belong to Christ (1 Corinthians 6:18–20; Ephesians 5:5). God's ways are best, even for our sex life. While Scripture is clear about the seriousness of sexual sin, it is equally clear that forgiveness is available through Christ for all who repent and believe in Him (1 John 1:9; 1 Corinthians 6:11). Believers do not need to be defined by past sin but are called to live transformed lives marked by holiness and obedience to God’s design (Galatians 5:19–21). The biblical view of sexuality is not restrictive for its own sake but protective and life-giving, leading people into the fullness of God’s good design.

FROM THE OLD TESTAMENT

• The Old Testament speaks against sexual immorality. God's design for sex is evident in the creation order: enjoyed between a man and a woman within the covenant of marriage (Genesis 2:24).
• God puts boundaries around sexual activity, as presented in passages like Leviticus 18:20–23, which prohibit adultery, homosexuality, and bestiality. These boundaries are not arbitrary restrictions but protective limits that preserve the holiness of the covenant, the dignity of the body, and the integrity of relationships.

FROM THE NEW TESTAMENT

• Sexual immorality is not just about behavior. Jesus notes that sins like sexual immorality come from the evil within the human heart (Matthew 15:19).
• Sexual immorality is the only explicitly valid reason for divorce (Matthew 19:9), showing us the seriousness with which God upholds sex in marriage.
• Sexual sin is uniquely described as a sin “against his own body” (1 Corinthians 6:18). Paul writes, “Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body.” Sexual sin misuses the body in a way that is distinct from other sins. 1 Corinthians 6:19–20 tells us why this matters: our bodies belong to God. We cannot submit to God but do whatever we want with our bodies. Sexual immorality is a violation of something that has been redeemed and set apart for God’s purposes.
  
• Ephesians 5:5 says, "For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God" (cf.  Galatians 5:19–21 and Revelation 21:8)  Our works do not save us, but they do show those who are true children of God. Though all believers may fall into sin, our lives should not be characterized by sin.
• The good news is that Christ died for our sins (John 3:16), so if we repent of our sins—including sexual immorality—God will forgive us (1 Corinthians 6:11; 1 John 1:9).

IMPLICATIONS FOR TODAY

You've seen the yards signs and bumper stickers: "Love is love" and "Love wins." Sounds good, right? To hear the world tell it, there are no limits on "love" (which often just means, sex).

But God says differently. God puts boundaries around sexuality because He truly loves us. He calls us to holiness in our lives, including our sexual behavior.

What does this mean for the man who lives with his girlfriend and then becomes a Christian? What about the young Christian woman whose friends laugh because she's a virgin? How should the man in a bad marriage who has "fallen out of love" with his wife think about sexual satisfaction?

Those who love God and want to serve Him will stay within the boundaries He has set. All people must do as Joshua told the Israelites: "choose this day whom you will serve" (Joshua 24:15). Truly God has the best plans for us, including our sexuality.

UNDERSTAND

• God means for sex to be between one man and one woman within the covenant of marriage.
• Sexual immorality is outside the bounds God has set and is a serious sin as it is more than just an action.
• True believers surrender even their sex life to Christ, fleeing sexual immorality.

REFLECT

• How has your view of sex been shaped by culture and what has been shaped by God's good design of it?
• In what areas of your life do you need to more intentionally “flee sexual immorality” rather than trying to manage or tolerate it?
• How does it change your mindset to remember that your body is not your own but belongs to God and that He has the best plans for your sex life too?

ENGAGE

• How does the Christian view of sex differ from the world's?
• How can Christians retain a biblical view of sex without coming across as judgmental or self-righteous?
• How can believers support each other in resisting or repenting from sexual sin?