How Can We Fight Sexual Sin?

Of all out-of-style words, chastity might be the most laughable today. The best way to be uninvited from anyone’s party is to be known for chastity.

But chastity is a powerful principle that can help God’s children flee the host of sexual sins that entice us. Chastity is shorthand for sexual appropriateness, or purity (see 2 Cor. 11:2 KJV). And God demands chastity “in heart, speech, and behavior” (Westminster Shorter Catechism (WSC) 71). Jesus offered this commentary on the seventh commandment: “Everyone who looks at a woman with lustful intent has already committed adultery with her in his heart” (Matt. 5:28). In other words, sexual fantasizing is on the same spectrum as adultery. Unwanted sexual advances are like rape. Pornography use is voyeuristic. Immodesty differs from prostitution only by degrees.

Instead of asking, “How far can I go?” chastity urges us to say, “How can I best honor God’s design for my sexuality?”

But Why Bother?

Is it really worth fighting sexual sin’s powerful magnetism? Yes! And Scripture’s two great commandments—love God and love your neighbor as yourself (Matt. 22:37–39)—summarize why.

Be chaste for God’s sake. God expects every Christian to “control his own body in holiness and honor” (1 Thess. 4:4.) Those committed to sexual sin disregard God (1 Thess. 4:8), but Christians are no longer “Gentiles, who do not know God” (1 Thess. 4:5). Chastity pleases God because it shows evidence of his saving grace.

Be chaste for your neighbor’s sake. Do not “wrong [your] brother in this matter” (1 Thess. 4:6). Sexual sin always has a victim. Pornography users, for example, promote sexual slavery, providing incentive for the trafficking of women and children. Nor does consent make sexual sin victimless. The willingness of a partner doesn’t cancel the consequences of disobeying God.

Be chaste for your own sake. “For this is the will of God, your sanctification: that you abstain from sexual immorality” (1 Thess. 4:3). Those enslaved to sexual sin radically hinder their sanctification and poison their entire walk with God. Most sexual sins create a voracious appetite for sexual gratification and numb the conscience to God’s voice.

How Can I Be Chaste, Like Jesus?

Keep “chaste company” (Westminster Larger Catechism 138).  Because “bad company ruins good morals” (1 Cor. 15:33), we have a duty to walk with friends who share our best goals. Godly company can also help satisfy our good desire for biblical intimacy. Our culture tragically conflates intercourse and intimacy. But while single people must remain celibate, they should not be starved for affection. “It is possible to have lots of sex and no intimacy,” Sam Alberry writes. It is also possible to be celibate, like Jesus, and experience real intimacy through deep friendships.[i] 

Don’t ignore the gift of marriage. As unromantic as it might sound, we may not dismiss Paul’s teaching, “It is better to marry than to burn with passion” (1 Cor. 7:9). Scripture lays down a practical duty of “marriage by those that have not the gift of continency” (WLC 138; 1 Cor. 7:2). It’s possible to sin by an “undue delay of marriage” (WLC 139).

Be sexually active in marriage. Married people must practice “conjugal love and cohabitation” (WLC 138). God is not a prude. From the start he urged married couples to be sexually active (Gen. 1:28). Marital love-making is one way couples frustrate Satan’s work (1 Cor. 7:5). Marital intercourse isn’t a cure-all; even the best sex can’t offset married people’s disobedience to their varied callings. But without it few couples will flourish.  

Become transformed. Don’t miss how Paul introduces his plea for sexual purity: “We ask and urge you in the Lord Jesus” to “abstain from sexual immorality” (1 Thess. 4:1, 3). Sexual sinners are only transformed as they receive Jesus’ righteousness for their justification and sanctification (1 Cor. 6:11). How can this happen?

  • Remember the length to which Jesus went to pay the penalty for your sin. He didn’t suffer so that we might go on expressing “the passion of lust like the Gentiles who do not know God” (1 Thess. 4:5).
  • Repent of sexual sin. Get honest with God and bring trusted spiritual friends into the conversation. If they’re true friends, they won’t be self-righteous about your sin; they know how hard it is to control their own bodies in holiness and honor (1 Thess. 4:4).
  • Receive the gift of true communion with Jesus. Share with him the joy he looked forward to on the other side of his cross-bearing (Heb. 12:2). Satan wants us to feel incomplete if we aren’t pursuing various sexual opportunities, but that’s because he’s lost the ability to know true satisfaction. He is always a chaser, never a finder.

In Christ Jesus we have the reasons and the resources to honor God’s will to fight sexual sin with chastity.


[i] Sam Allberry, Seven Myths about Singleness (Wheaton, Il.: Crossway, 2019), 50.

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