Mental Pornography: Winning the Battle with Lust

One of the most compelling tales in the Old Testament is the story of Samson and Delilah. It's a narrative that has captivated audiences in Sunday School classes, sermons, and even Hollywood films. The tale is fascinating because it offers a vivid illustration of how a man can be utterly undone by his desires, abandoning common sense and devotion to God in pursuit of fleeting pleasures.

What makes Samson’s story particularly intriguing is the contrast between his physical strength and his moral weakness. Samson was considered the strongest man in Hebrew history, capable of single-handedly defeating entire armies. Yet his downfall didn’t come at the hands of a mightier warrior, but rather through the deceptive allure of a woman. Samson’s lust ultimately led to his undoing, serving as a cautionary tale for countless others who have followed a similar path to ruin.

Lust is a powerful force, and it has been the cause of downfall for many throughout history. From defrocked pastors to disbarred judges, from disgraced politicians to impeached presidents, the desire for sexual gratification has been a thorn in the side of men for ages. It’s a sin that has destroyed families, ruined careers, and shattered lives.

In the Sermon on the Mount, Jesus deals directly with the sin of lust. He explains that the Law of God goes far beyond mere outward obedience. The Law’s true purpose is to address the heart’s intentions, not just external actions. In Matthew 5:27-30, Jesus challenges the superficial understanding of the Law regarding sexual purity, showing that God requires more than just abstaining from physical acts of sin; He also demands that we flee lust as well.

I. The Letter of the Law: "You Shall Not Commit Adultery"

In Matthew 5:27, Jesus begins by quoting the seventh commandment: "You have heard that it was said, 'You shall not commit adultery.'" The term "adultery" (Greek: moicheuo) is understood both in ancient and modern contexts as a violation of the marital covenant, an act of infidelity that betrays the trust and fidelity that marriage is built upon.

Why is adultery such a grave sin that it’s included in the Decalogue, the Ten Commandments? Because it is fundamentally destructive. Adultery shatters trust, creates emotional and relational barriers, and opens the door to a host of other sins and heartaches. It’s pervasive and insidious, creeping into the lives of many, often with devastating consequences.

The New Testament, like the Old, is filled with warnings against sexual immorality, which includes adultery. In passages like Ephesians 5:3-5, 1 Thessalonians 4:3-5, and 1 Corinthians 6:13-20, the apostle Paul admonishes believers to avoid sexual sin, emphasizing the need for purity and self-control. Solomon’s Proverbs also warn against the seduction of sexual immorality, portraying it as a path that leads to destruction and death (Proverbs 5:1-6).

Despite these clear warnings, Jesus’s critics in His day—particularly the scribes and Pharisees—taught that external adherence to the commandment was sufficient. They believed that as long as one didn’t physically commit adultery, they were keeping the Law. However, Jesus reveals that this superficial interpretation misses the true intent of God’s command.

II. The Spirit of the Law: Lust Is the Root of Sexual Sin

In Matthew 5:28, Jesus delivers a powerful truth: "But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart." Here, Jesus takes the commandment against adultery to its true depth, addressing not just the act but the heart’s desire that leads to the act.

Some might think that Jesus was introducing a new, more radical interpretation of the Law. However, the condemnation of lust was not new. The tenth commandment forbids coveting, which includes desiring another man’s wife (Exodus 20:17). The prophet Jeremiah also denounced the lustfulness of the Israelites, which led to their judgment (Jeremiah 5:7-9).

Jesus’s words condemn the act of looking at a woman with "lustful intent." The Greek term used for "look" (blepon) indicates a prolonged gaze, not just a passing glance. This isn’t about noticing someone’s beauty; it’s about staring with the intent to fuel lustful thoughts.

Lustful intent (Greek: epithymeo) means to set one’s heart upon, to covet or desire something illicitly. It’s the root of sexual sin, the internal sin that precedes the external act of adultery. Evangelist Ray Comfort aptly describes it as "mental pornography," an apt term for the kind of internal sin Jesus condemns.

III. The Application of the Law: Removing the Sources of Lust

Jesus doesn’t stop at identifying the sin; He also provides the remedy: radical amputation. In Matthew 5:29-30, He says, "If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell. And if your right hand causes you to sin, cut it off and throw it away. For it is better that you lose one of your members than that your whole body go into hell."

Now, before anyone runs to the nearest sharp object, let’s clarify: Jesus is not advocating literal self-mutilation. He’s using hyperbole to make a point. The root issue isn’t the physical body; it’s the heart. Even if a man were to gouge out one eye, he could still lust with the other. The sin Jesus addresses is internal, and thus the solution is to "cut off" the sources of temptation.

In practical terms, this means identifying and removing those things in our lives that lead us into lust. If certain places, situations, or media cause us to stumble, we must avoid them. For some, this might mean avoiding certain TV shows or movies; for others, it might mean avoiding the beach or even putting strict controls on internet use. The principle is to "make no provision for the flesh, to gratify its desires" (Romans 13:14).

Consider the story of David and Bathsheba. David, a man after God’s own heart, fell into adultery not because he planned it, but because he allowed his lust to grow unchecked. Had David turned away his eyes the moment he saw Bathsheba bathing, he might have avoided a cascade of sins that ultimately led to murder and national scandal. David’s story is a sobering reminder of how easily lust can lead to devastating consequences if left unchecked.

Conclusion: A Call to Depend on Christ

The teaching of Jesus in the Sermon on the Mount is a call to recognize our deep need for Him. When we understand the full extent of God’s Law, we see how far we fall short. While most of us might not have committed physical adultery, we’ve all fallen short in our thoughts and desires.

This realization should drive us to Christ, the only One who has perfectly fulfilled the Law. Jesus never looked at a woman with lustful intent; every thought He had was pure and holy. His perfect obedience is our hope, for it is His righteousness that is imputed to us through faith. 

This doesn’t mean we’re free to continue sinning. On the contrary, Christ’s example should encourage us to cut off anything that leads us into sin and to strive to live in obedience to Him.