Killing Sexual Sin | Matthew 5:27-30

June 26, 2016 Preacher: Ryan Gilbert Series: Sermon on the Mount

Topic: Lust, Adultery Scripture: Matthew 5:27–30




This morning we are continuing Jesus’ Sermon on the Mount, which is continually getting more and more challenging, and more and more specific. This is some of the most challenging teaching in all the Bible, and today is no exception. Today Jesus brings up what is probably the most prevalent secret sin there is…not just out there in the world, but in the church.

Jesus is over and over speaking to the inward nature of real obedience. Again and again, he’s correcting the overly legalistic attitude of the scribes and the Pharisees, this attitude that was all about the external, even when it came to sexual sin. Jesus makes clear that this isn’t just about not cheating on your wife or your husband. It’s much more than that.

Even in the world that we live in, which is completely immersed in sexual images, sexually-explicit marketing, pornography, and immodesty, God calls Christians to do something that is incredibly rare in our society, basically unheard of. Jesus calls us to physical purity, yes, but also to mental and emotional purity. Our hearts are to be so in love with God and so committed to our wives and husbands that the only sexual thought that crosses our mind is of them. If you’re single, God calls you to something, again, basically unheard of and incredibly rare in our society: physical and mental purity; Saving your sexual desires and thoughts for when you are married. Let’s read what Jesus has to say in Matthew 5:27-30.

“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. 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.”

Freedom from Bondage to Sin

The beauty of this text is not only that it gives us a definition of sexual purity from Jesus Himself, but it also gives us specific steps toward sexual purity. Now before we get to these steps of Godly sexuality, I must mention something:

Sometimes when we read the Bible, we can feel a sense of defeat. How are we supposed to really live up to these standards? I ask this question often. Sometimes it seems impossible! Let me just say, that feeling of inability is a good thing! We have no ability to live up perfectly to the standards that God has laid out in His Word. In fact, it’s that very truth that reveals to us our desperate need for a Savior, the only One who WAS able to live up to God’s standard, the only One who didn’t have his own sin to pay for, and therefore could pay for ours. His name is Jesus.

Ultimately, we pursue Godliness and purity not because our salvation depends on it, but because we are slaves who have been set free. We are right with God because of what Jesus did, and now we are free from the bondage of sin, free to live for His glory unhindered by habitual sin. If you haven’t turned and placed your faith in Christ, you have no freedom from sin. You may be able to get rid of certain things and certain habits, but ultimately, true freedom from the penalty and the power of sin is only found in Christ. So, I just want us to have that framework in mind when we come to this text, and the areas of Godly sexuality that Jesus reveals.

So, even though we’re free from the bondage of sin, we still struggle, sometimes struggle greatly, particularly with sexual sin. So how, as believers, do we kill adultery in our hearts? The first area that Jesus focuses in on:

The External: Commit physically to your spouse.

Now the main thing Jesus is getting at in this text is not just the external, but the internal. If you recall (if you’ve been here the last few weeks), that’s what he’s been getting at throughout this sermon on the mount, that God cares not only about murder, but anger. Not just adultery, but lust. But, as I mentioned last week, Jesus is not dismissing Old Testament teaching, but in fact expounding on the heart of the Old Testament teaching on murder and adultery.

In verse 27, what he says is still absolutely true: “You have heard that it was said, ‘You shall not commit adultery.’” This is still an incredibly important commitment for those who are married. Part of the covenant of marriage is an absolute commitment to staying faithful to your spouse physically. It’s the seventh commandment, Exodus 20:14. There is clearly a sanctity of marriage in the same way that we see a sanctity of life reflected in the sixth commandment, “You shall not murder,” which we looked at last week.

Marriage is such a beautiful gift from God that adultery, in the Old Testament, was punishable by death! To consider this wonderful gift from God called marriage not enough to please me, was so offensive to God that breaking this marriage covenant by committing adultery would warrant you death in the Old Testament. Imagine parents buying a teenager a brand new car for his 16th birthday, and then the teenager saying, “Ugh, I wanted a green one.” That’s probably offensive for you as a parent, but seeing God’s great gift of marriage to your spouse as not enough is far more offensive to God. Why? Because we don’t see how great of a gift it is!

Why is it that the marriage covenant is so sacred? Not just because it’s a gift from God, but also because in a biblical marriage we see the unique image and glory of God. Genesis 1:27 reveals to us that God made us in his image, both male and female. It’s man and woman that bear the image of God. This unique image and glory of God is what’s at stake in a biblical marriage.

This is also why God uses the picture of marriage to describe his own relationship with the church. Because this picture best displays his image, his glory to the world. Seeking to have a healthy, God-centered marriage is not important just because it will make you more happy, though it absolutely will; It’s supremely important because it represents the glory of God.

But even this most basic, foundational commitment of marriage is under attack in our culture. Increasingly, people are no longer seeing the necessity of closed relationships. At least, that’s what it’s come to be known. That’s the terminology to make it seem like a negative thing: closed relationships. Why not be open? Not only is cheating becoming more and more common, but these open relationships, in which the husband and wife even mutually conclude that it’s ok to seek out other relationships, are becoming more and more common.

As Christians, we know that the Bible is very clear on marriage. At the heart of the human experience, broadly, is monogamous marriage between a man and a woman. This is the only celebrated and commanded picture of marriage in the Bible.

I know that for many of us in this room, this may seem like an issue far removed from us. We know this. And we know we’d never cheat; we don’t have that in mind whatsoever. But most people that cheat, and you might be surprised by this, they didn’t exactly have it in their mind in the beginning to go out and cheat. I’m sure that’s sometimes the case, but most of the time it’s not the case at all! It was just a friend at work, that they got to know really well, and it turned into something they never expected. This is why, especially for believers, we must guard against marital unfaithfulness. A common first step in moral failure is thinking that you are above moral failure!

Some signs that might help you put some flags up:

  • You go out of your way to have regular interaction with someone, someone you might be attracted to. Maybe you even rearrange your calendar.
  • You start to become more critical of your spouse, especially when compared to this other person that maybe you’ve romanticized.
  • Your desire for your husband or wife, physically and even emotionally, starts to dwindle.

If this is you, my plea is this: Get help, and renew your commitment to your spouse and even more-so to God. The external command from God: Commit physically to your bride, or your husband. The next area that Jesus address is the Internal:

The Internal: Commit your heart to your spouse.

Verse 28: “But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.” Jesus is getting now at the heart of adultery. Every sinful act starts where? In the mind. He says “Everyone who looks at a woman with lustful intent.” The word for “look” here implies a continuous looking, like a second glance. The purpose of this looking is to lust. Now the word “lust” literally means desire, usually a strong desire. In this context, obviously, we know that Jesus is referring to sexual desire. There’s nothing wrong with lust in and of itself, unless it’s in a context outside of God’s will. To lust after your wife or your husband is good thing! In fact, let me just say it, “Get to lusting!” That’s one pastoral encouragement for you today.

But to look at a person, in a movie, on a computer, on your television, on the beach, with the purpose of thinking thoughts and being sexually stimulated, that is adultery. In the world, unfortunately, it’s almost a given that you be exposed to sexual temptation, the temptation to lust. You can’t drive down an interstate without seeing a billboard. You can’t walk through the line at the grocery store without seeing a magazine. You probably can’t go anywhere outside your house in the middle of the summer without facing the temptation to lust.

There’s nothing sinful about being tempted. Jesus himself was tempted in every way and yet did not sin, that’s Hebrews 4:15. Temptation in this world is impossible to avoid completely, but Jesus says that looking with the purpose of satisfying our lustful desires is adultery. This isn’t just for men, even though it addresses men here. By implication, the exact same is true for women. And maybe for women, the struggle here is more often emotional lust that physical lust.

His main point here is that sin is not relegated to external actions alone. God does not call us only to look pure, but to be pure. Part of being pure is that our hearts and minds belong to Jesus. What that means when it comes to our sexuality is that we’re to commit even our thoughts to our marriage! The way we commit our hearts to our marriage, is by committing our thoughts to our marriage. Why? Because, the battleground for your heart is your thought life. What do you think about? What images or people do you recall or dwell on? What do you fantasize about? We’re not just called to physical purity; we’re called to mental purity! We’re called to commit our hearts, which is every part of ourselves, to our marriages, and in that way we obey God and fulfill part of God’s ultimate purpose for marriage. As I mentioned earlier, that ultimate purpose is to reveal God’s image and glory to the world.

There are many practical things we’re about to talk about to kill lust, but first I wanted to address openly what is probably the biggest fuel for lust in our world in the 21st century, and that is pornography.

  • One study I read this week revealed that 15% of all web searches are for erotic content.
  • 1 in 5 Google searches on smartphones are for pornography.
  • 79% of men between 18-30 say they view pornography at least 1x/month.
  • 67% for men between 31-49. 49% of men between 50-68.
  • For women, 76% for those 18-30. 16% for those 31-49. 4% 50-68.
  • These statistics are from the Barna Group.

Now if you think maybe this doesn’t apply to families, somehow that they’re exempt from these statistics, let me read you a quote: “Never before in the history of telecommunications media in the United States has so much indecent (and obscene) material been so easily accessible by so many minors in so many American homes with so few restrictions.” Here’s the crazy part. That quote is from the U.S. Department of Justice in 1996—20 years ago. Today, some researchers place the average age of a child first viewing pornography at nine years old, on AVERAGE.

I hope this breaks our hearts, as parents and as Christians. But I also hope this wakes us up a little bit. If you have a teenager who has unfiltered access to the internet at all, it is very likely they are already addicted to internet pornography. For Christian children and teenagers who grow up addicted to pornography, it’s as if they start their fight for purity with a knife wound. They’re already addicted and bleeding before they ever desire to fight for purity. This must grip us.

Things have changed so quickly with the internet, access not only through internet browsers but even through smartphone apps. You’d be shocked to know just how many roundabout ways there are to access an internet browser through many of these apps that seem harmless.

The first time I ever saw pornography of any type was when I was nine years old. I was at a sleepover with a few friends, and one of them knew where his dad had a pornographic DVD hidden. This is a family we absolutely loved and trusted, truly a wonderful family. But the dad had a DVD that his wife didn’t even know about, but his son did. If you have pornography in the house, or if you look at pornography online, it is incredibly likely that your kids are as well, or at least will be soon. But even if you don’t, please do not allow unfiltered internet access. I have some of the best parents in the world. The only computer in the house when I was growing up was in their bedroom, and it was in the corner in a position in which you could see it from any part of the room, including the hallway. It seems like a pretty safe place. But, I must say, it didn’t stop me from using it to access pornography.

The reason I tell you this is because when I was in high school, the smart phone didn’t exist. But if just the accessibility I had was enough for me in Junior High and my freshman year of high school, these unfiltered free-reign smart phones are pretty much guaranteed tools of the enemy. I don’t want you to turn into overly-protective parents, but I do want to give you some practical things to help with these issues as part of this last area that Jesus focuses in on: This last area of Godly sexuality that Jesus focuses in on is:

Disciplines: Discipline yourself for Godliness.

The ultimate reason that we lust and look at pornography is because we don’t esteem Jesus highly enough. We’re drowning in what we see as the beauties of the world, and so are blinded from Christ’s full beauty. The ultimate goal in getting untangled from any habitual sin like lust, sin that many people don’t even know that they do because they do it so often, the ultimate goal is to run the race unhindered– To live our lives for the glory of God with the Great Commission as our ultimate goal and mission. We kill sin because we don’t have time for distraction. This is the reason Jesus tells us not to mess around with sin. Look at verses 29-30 with me again:

“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.”

Wow. Sin is SERIOUS! We all have struggles, yes, but sometimes we need to recognize that those “struggles” are rebellions against God! Jesus takes sin so seriously that he says here that “it is better that you lose one of your members than that your whole body be thrown into hell.” In case they weren’t hearing him clearly enough, he says it twice! And he’s not saying that if you ever commit adultery or lust that you’ll go to hell. He is saying that part of repentance and faith is not living a life marked by adultery or lust. A truly born-again Christian will struggle and will sin, but will never give up fighting it.. So we cut it off.

Now, I hate to weaken this in any way, but we need to know Jesus is not actually saying cut off your arm. He’s speaking figuratively, but why? Because he wants to be so clear the utter necessity of killing sin, nipping it at the bud. And it’s not just about killing sin, but getting rid of anything that causes you to sin, or even tempts you to sin.

This means that there are things we must be willing to cut out of our lives for the sake of Godliness, for the sake of killing sin. So, some practical thoughts, practical boundaries to help us enjoy sex as the gift that God made it to be, and also to help our marriages reflect the glory of God in the Gospel:

How do we kill adultery? (before we get to lust)

  • First, if there is someone that you may be emotionally attracted to, it may not even be sexual attraction yet: you may need to cut this relationship out of your life. We’re to be willing to do drastic things to cut sin from our lives, including taking preemptive This is for men and women, please hear me: emotional intimacy is the lifeblood of adultery, of affairs.
  • Another thing I’d encourage, and maybe you think this is extreme, maybe you have to navigate what this looks like for you, but something I’ve tried to commit to is not having private conversations with women, at all, which is difficult as a pastor. But I try to make sure someone is around. They don’t have to be listening in, but the door is never shut. Even Facebook messages, I try and always courtesy-copy my wife. Again, this may seem extreme, but it’s not as extreme as cutting off your arm! And that’s what Jesus said…so, haha!

How do we kill lust?

  • The first step to killing lust, for those of you who are married, is to recognize the beautiful gift that God has given you in the sexual intimacy between you and your husband or wife. Recognize it as beautiful as it is, ultimately a picture of the Gospel and how much Jesus loves his bride the Church. See the beauty of that intimacy to which all other beauties pale in comparison. The world has nothing to offer that is as good and beautiful and intimate as that.
  • The second thing I want to mention, for those of you who really struggle with lust, you will have to completely retrain your brain. It may take some time, but it is possible. It’s called bouncing the eyes. As soon as you see some sort of sensual image, you just bounce the eyes and look elsewhere. That’s a habit that you can form.
  • The third way to kill lust: cut things out of your life that put you in positions where you are unnecessarily tempted. For some of you, this means not going to the pool, or to the gym. Buy some weights at Wal-Mart. Do what you need to do to kill lust, and be absolutely faithful to God, first, and then also faithful to your wife or husband, even mentally.
  • Fourth specific way to kill lust: memorize Scripture! 1 Cor. 6:18- “Flee from sexual immorality.” Straight up flee! Run! Memorize that, and it will remind you to run away from temptation. I’ve heard people say, “You can’t always from temptation.” Why not!? Sure, there might be times you can’t run, but it seems like most the time you can run. Another verse to memorize 1 Cor. 10:13! This is a bullet in your spiritual gun that can help you kill lust! 1 Cor. 10:13- “No temptation has seized you except what is common to man, and God is faithful, he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can stand up under it.” Maybe you justify your sexual sin: “I can’t help it. My wife doesn’t want to be intimate anymore, so I just can’t help it.” Having this verse hidden in your heart will not allow you to justify it.
  • The last specific way to kill lust, for those of you who struggle with it, is to kill pornography.

How do we kill pornography?

  • Take preemptive measures, before the temptation comes. Don’t wait until it’s a problem. All alone in your room, home alone, full internet access, and nothing to do, that’s probably not the best time to suddenly start fighting temptation. Start before that point. Start with accountability.
  • Accountability: You must have someone in this church or a strong Christian friend whom you can talk with regularly. And not just to confess after the fact, but to hold you accountable. has immediate filtering and accountability for your whole family for $14.99. Well worth the investment. has free accountability software- it emails an accountability partner every week listing any questionable sites visited. I’ve had that on my computer for more than a decade now. Again, a common first step to moral failure is think you’re above moral failure. As your pastor, I do not assume that I’m above that. None of us should. So seek accountability.
  • Ultimately, maybe the preemptive measure you need is to cut off your arm: get rid of your lap-top, and figure out the inconveniences. Get rid of your smart phone. Did you know that dumb phones do still work! They do. I know they don’t look cool, but they work, and some of these dumb phones work just as well as smartphones.

Those are just some really practical things to help you think through killing lust. I hope, though, that for those of you steeped in sexual sin, that you would be bold enough, today, to confess that to an elder or a strong Christian friend. Sin causes us to think inaccurately, it skews how we see reality. If you don’t realize just how much your sexual sin is distracting you from your purpose on earth; If you don’t realize just how much your sexual sin is slowly eating away at your mind and heart, you’ve been duped. But let me just tell you, not only does Jesus says, “Come to me, trust in me, and your guilt is taken away, you are washed clean!” But he also says, “Give me your heart fully, and I WILL KILL THIS SIN. You CAN be free, by the power of God.” This is not something that God cannot handle. Be bold, share with someone, and let them help you give it over to God.


When Jesus addresses lust here, he’s not encouraging us to weaken all of our desires. He’s not saying we’re too passionate. Maybe sometimes we’re too driven by emotion or passion or how we feel in the moment, but on a very real level, God has never said to lessen your nature as a passionate being. In fact, I think the opposite is true. C.S. Lewis, in a very famous quote, puts it this way:

“It would seem that Our Lord finds our desires not too strong, but too weak. We are half-hearted creatures, fooling about with drink and sex and ambition when infinite joy is offered us, like an ignorant child who wants to go on making mud pies in a slum because he cannot imagine what is meant by the offer of a holiday at the sea. We are far too easily pleased.”

The fight for sexual purity is not a fight against what will bring us happiness. It’s a fight against an inferior happiness. Don’t waste your time with porn, or fantasies of other men or women, or anything else that just distracts us from the greatest, most pure joy and pleasure to be found in Christ, unhindered by habitual sin. The battle for purity is really a battle for finding your absolute joy and pleasure in God.

Don’t settle for less. Don’t settle for the mud pies. Pursue God’s beautiful design and plan for sexual purity. Let’s pray.