Why Is Sexual Immorality Such a Big Deal?

The temptation to single out one type of sin or one category of sinner as uniquely worthy of condemnation is common. It often springs from and feeds the self-righteous hypocrisy of our hearts, which seeks to find a point of comparison by which we can stand over another as morally inferior to us. This temptation is especially strong when the sin to which another person is tempted is one to which we feel no attraction whatsoever or which we find safely unattractive. Because we are confident that we would never do that, we find it easier to treat the person who would as particularly depraved. It is useful to our proud hearts precisely because we are sure that we are not personally susceptible to this depravity.

And yet it would be wrong for us to react to this possibility of self-righteous judgment by taking a ho-hum, cavalier attitude toward sexual sin and temptations. In the Bible, sexual immorality is a big deal. Most who are familiar with Scripture sense this. The subject of sexual immorality comes up often and is treated with heightened seriousness.

So here is our challenge: How do we understand and heed the seriousness of the Bible’s concern over sexual immorality while not giving space to our impulse to look down on others? I suggest three perspectives to help us maintain a proper biblical concern for sexual immorality without being self-righteous:

  1. Have a biblically high view of sexuality.

In 1 Corinthians 6:12–20, Paul explains to his readers why sexual immorality is so serious: It’s because sex is so precious. Paul opens his discussion by quoting a typical cultural understanding of sex—that it is just an appetite, a biological drive to be fulfilled: “Food is meant for the stomach and the stomach for food” (6:13). Paul contradicts this directly with, “The body is not meant for sexual immorality, but for the Lord, and the Lord for the body.” His point? This is not a mere issue of appetite, a biological need for the flourishing of the human animal. Human sexuality is not primarily biological; it is theological.

This assertion alone is in radical conflict with almost all that our culture believes and teaches about sexuality. But the further we go into this truth, the more incredible it becomes. For Paul goes on to describe the content of the theology of sex, which is nothing less than union with Christ: “For, as it is written, ‘The two shall become one flesh.’ But he who is joined to the Lord becomes one spirit with him” (6:16–17). He says the same thing to the Ephesians, “’…and the two shall become one flesh.’ This mystery is profound, and I am saying that it refers to Christ and the church” (5:31–32). We have only begun to plumb the riches of biblical teaching on the ways that sex as God designed it displays to us the wonder of the salvation given to us in union with Christ. His lavish love and delight in his Bride, the intimacy and affirmation of his setting apart his Bride as belonging to him exclusively, the safety of his commitment to never leave or forsake her—these are a few of the enormous gospel realities which true marital sexuality was designed to picture. Sexual immorality, in all its forms, destroys this picture.

David White says it this way:

“Sexual sin damages the self in a way that is unique, unlike any other sins. Why? Paul points to the profound mystery, reminding that sexuality is a reflection of the ultimate union with Jesus. Sexual sin dilutes the greatest wonder in the universe. The glorious hope of the world to come is living in a face-to-face relationship with Jesus—of which marriage and sexuality is the closest terrestrial analogy.”¹

In summary, sexual immorality is so serious because it corrupts and deprives us of something so good.

  1. Respect the personal and relational power God has given to sexuality.

No one needs to be convinced that sex offers powerful pleasure. The ubiquity and endless variety of options in sexual immorality reflect the pursuit of this pleasure. But lingering beneath our fascination with sexual pleasure, there remains a sense that something more profound is involved, something deeply personal and enduring. The Bible teaches that sex cements the bond of a husband and wife in a lifelong union (Mark 10:8–9). In some mysterious way, this bonding aspect is still present even when we rip sex out from its lifelong, marital context, as Paul explains, “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 shall become one flesh’” (1 Corinthians 6:16). We can try to take sex out of the marriage bond, but we can never completely take the marriage bond out of sex. It’s just the way God made it.

As it turns out, there is even a biological component to this bonding. The pleasure of sex corresponds to the powerful release of certain chemicals that have the effect of forming a strong social bond.² On the one hand, this is a wonderful reality that should fill us with gratitude and praise. “Our bodies are the splendid interweaving of the physical and the spiritual. God’s design of our physiology should generate deep awe and worship.”³ But the dark side of this is that all forms of sexual immorality unleash this bonding power in destructive ways. As Paul says, “He who is joined to a prostitute becomes one body with her.” Or, as William Struthers warns concerning the use of pornography, “Unfortunately, with repeated sexual acting out in the absence of a partner, a man will be bound and attached to the image and not a person.”⁴ Imagine how this damages a future or present marriage. This biological bonding effect is also part of the reason people can speak of sexual addiction. Everything you do sexually contributes to a physiological momentum that builds toward a bondage not easily broken.

Sex is powerful. God made it so. This makes misuse of sex especially dangerous personally and relationally.

  1. Know that all humanity, yourself included, falls short in God’s design for sexuality.

Notice that my first two points do not apply to just one type of sexual sin. They are based on what sex truly is, the meaning God designed it to communicate, and the relational power God gave it. Every departure from the original design defaces the picture and abuses the power. Isn’t this Jesus’ point when he said, “You have heard that it was said, ‘You shall not commit adultery.’ But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart?” (Matthew 5:27–28). Jesus did not say it leads to adultery; it is adultery in the heart. It is an act of the heart that misuses sexual pleasure and violates its gospel-shaped design. Who of us is qualified to throw a first stone (John 8:7)? It is spiritually dangerous to focus moral concern on one kind of sexual sin without recognizing the commonality with our own transgressions.

If we have the Bible’s high view of sex as a picture of the Church’s union with Christ and a respect for the power God has given it, we will not only take sexual sin very seriously, but we will also examine ourselves, confess the many ways we have failed to desire and fulfill God’s perfect design, and cast ourselves again and again at the mercy of the gospel. Yes, sexual immorality is a big deal, so let’s keep pointing each other to our only faithful Bridegroom.


¹  See David White, God, You, & Sex (Greensboro: New Growth Press, 2019), 148.
²  See William M. Struthers, Wired for Intimacy (Downers Grove: IVP, 2009), 105.
³  God, You, & Sex, 82.
Wired for Intimacy, 105.