I really like fire. Whether at a campsite or on the couch, to me fire is a thing of wonder. I like building it, I like staring at it, being warmed by it, even jumping over it when it’s relatively safe to do so. Anyone with me? Let me ask you a question about fire: in a home where is fire good? A fireplace. In the fireplace, fire isn’t just good, it’s very good. It warms the whole house. It gathers and draws others in. It pushes back the cold. Fire in the fireplace is a gift. Next question, in a home where is fire bad? Anywhere else. Fire out of the fireplace doesn’t warm a home, it burns a home down.
This morning I start with fire because the root of adultery is exactly that…a flame, a flicker, a spark that leads to a great blazing fire. When this fire is kept in the fireplace of marriage, it warms a whole life. But let that fire loose outside marriage, it only does one thing very well: it destroys.
This commandment begs some hard questions. Are any of you in these fires right now? Maybe you’re already involved in or planning to begin an adulterous affair? Making you’re planning a secret meet up sometime soon, even loosely, just to be somewhere alone with someone you shouldn’t? Or, maybe you’re enjoying those extended glances where you lingering in a coworker’s eyes, or maybe you’ve gone back and reread their texts a few times too many? Or, maybe you’re indulging in explicit images online, or chatting with someone you shouldn’t?
I don’t ask these questions to shame anyone here. But to prepare you for to hear the seventh commandment today. So if you answered yes to any of the questions just now…stay with me, and keep listening. There is a deep rebuke here to hear and heed, but there’s more grace here than you think.
We’ve got two headings to work through today. See first…
The Negative Command
In the original Hebrew the seventh commandment is stated just like the sixth commandment, with a brief and brutal simplicity. These commandments only contain two words, “No murder.” and “No adultery.” Let’s begin simply, and just ask the question, what is adultery? Sadly, it can take many forms. I think a broad definition is helpful, perhaps we could put it like this: adultery is giving that which belongs to your spouse alone to someone else. This could be romantic affection, desire, and devotion, whether or not it ever becomes physical. Or we could say, adultery is relating to another person in a way that dishonors the marriage covenant, whether physically or emotionally, inwardly or outwardly. All in all, adultery and adulterous actions don’t always require a bed. The key ingredient in view is one giving away what belongs to spouse alone.
This is the pattern. God defined marriage. We don't get to redefine it…not to two women, not two men, not one man and his neighbor’s wife, and not one women and her neighbor’s husband. By crossing these lines, the adulterer isn’t just breaking a rule, they’re bowing to the altar of self instead of God. That’s clear.
There was a time when this was not clear. In 1631, the royal printers in London ran a new edition of the King James Bible. Somewhere in the printing process, one word got left out from Exodus 20:14. Just one, the word ‘not.’ So, the final version of the seventh commandment as it stood in the text was, “Thou shall commit adultery.” Once this was discovered the printers were fined and stripped of their license. The King hired and sent out groups of book hunters to track down and destroy as many copies as they could find. History remembers it as The Wicked Bible. Today only fourteen copies survive in museums.[1] Our Bibles don’t make this mistake, so this commandment ought to be clear to us as well.
Let’s trace how this was dealt with in Scripture. Adultery existed before the giving of the Law, perhaps most notably were the adulterous attempts made by Potiphar’s wife toward Joseph near the end of Genesis. Like this situation, wherever adultery occurs, dreadful things follow. We find it next in the seventh commandment. It’s included elsewhere too. Leviticus 20:10, “If a man commits adultery with the wife of his neighbor, both the adulterer and the adulteress shall surely be put to death.” Deuteronomy 22:22 repeats the sentence almost word for word. That the death penalty is present as a consequence shows us how far back this transgression goes, it goes all the way back to creation. Before the fall, in Genesis 1-2, God joined male and female into one flesh, and what God joined together, no one is to separate. One man, one woman, becoming one flesh.
Israel broke this commandment many times physically. In Numbers 25, Israelite men joined themselves to pagan prostitutes, who lured them out of the camp to join in pagan worship.
More famous is David’s adultery with Bathsheba in 2 Samuel 11. In this moment David stays home when he should be at war. He gets lazy when he should be diligent. He let his eyes wander when he should have guarded them. These adulterous thoughts led to actions that produced a physical affair. He called for a woman he should’ve left alone, took her for himself, only to try and cover it up by deceiving her husband, ultimately leading to the death of her husband, the death of their child, and the disruption of the Kingdom.
We could also speak of Proverbs 5-7 where the wise father repeatedly warns his son of going near the adulteress’ house. She is portrayed as alluring, enticing, seductive, and deadly. The father clearly warns his son, that all who go down to her house will only find death.
That’s some of how Israel broke this commandment physically. But they also broke it spiritually. What do I mean? God uses the imagery of adultery to rebuke His people for being idolatrous in heart. So while not committing physical adultery, Israel often committed spiritual adultery. The golden calf is such a moment, when they made their own image and worshipped it instead of God. In Jeremiah 3 God asks Israel, throughout all the land, on what hill “…have you not been ravished? … you have the forehead of a whore, yet you refuse to be ashamed.” In Ezekiel 16 God says something similar, rebuking Israel for their adulterous hearts which had repeatedly turned away from Him to idols. And the whole book of Hosea puts this on display as God likens Israel to the prostitute Gomer, and rebukes His people for having hearts that continually run after other gods, as Gomer continually ran after other lovers.
And when Jesus comes He raises the bar. In Matthew 5:27-30 He says, “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... 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.” Jesus isn’t contradicting the seventh commandment here, He’s raising the bar by pointing out its true meaning. Lust in the heart is far more than a mere thought, it’s adulterous at root. Paul continues to expand on this by giving a number of warnings against adulterous living, saying at one point that those who indulge in such sin live as if they’re pagans who don’t know God (1 Thess. 4:1-9).
Bottom line Church? Whether it’s physical adultery or spiritual adultery in view, there’s no small version of this sin. It’s all dishonoring to God and deeply hurtful to others. Thus, hear and heed the command. Hear God love you by warning you against that which will destroy you. Adultery is a fire that destroys. Know it. Embrace it. Flee from it.
‘But pastor, I have such strong desires and temptations.’ It doesn’t matter, are you not more than your feelings? Are you not more than your temptations? Are you more than an animal in heat? Of course you are! You’re an image bearer, remember it and act like it. Though desires might be great, sexual desire is not a craving we’re free to satisfy in any manner that pleases us. Sometimes obeying this command will mean we must change something. It might look like finding a new group of friends, or forgoing certain forms of entertainment for a time, or indefinitely.[2] Sometimes obeying this command means you unlearn bad habits and learn some new ones. There is no excuse. Self-denial is a real discipline we must pursue until it become our habitual practice, and self-control is a real fruit of the Spirit God has given all His children.
Church, obedience to this command is right. Hear and heed the negative command. But don’t only do that. Hear and heed the…
The Positive Command
Here’s something important about how God’s commandments work. When He tells us not to do something, He’s also telling us to pursue something in its place. Yes there is the ‘Thou shall not…’ but there is also the ‘Thou shall…’ to each commandment. We’ve seen what the seventh commandment calls us away from, now ask a different question. What is God commanding us to pursue in the seventh commandment? The answer to that question is simple I think. The Heidelberg Catechism we recited earlier told us plainly, we must not only detest adultery but must also “live chaste and disciplined lives, inside and outside of holy marriage.”
Or in other words, since the sin of adultery is what is to be avoided, the virtue of faithfulness is what we must pursue. Faithfulness to God in singleness and faithfulness to God and spouse in marriage. Or as H.B. Charles Jr. puts it, the seventh commandment doesn’t just restrict pleasure, it relocates it.[3] God isn’t anti-pleasure. He’s the one who invented it, and in this commandment He’s telling us where pleasure is safe to run wild.
So how do we actually pursue the virtue of faithfulness? Three ways.
1) Keep Christ as Your Highest Satisfaction
Married or single, your first desire must be Christ. You were made for the glory of God before you were made for marriage, which means no person on the planet was ever built to satisfy you completely. Not a boyfriend. Not a girlfriend. Not a spouse. Not your kids. Only Christ can carry that weight. So, stop hunting for a soul mate. You could meet a thousand people who check every box on your list, and in each instance you’ll still find that it’s only Christ who actually satisfies. Thus, the seventh commandment invites us all to seek after Christ first, and find in Christ our all.
2) Starve the Wrong Fire
It is human to have sexual desire, and temptation is not sin. It’s not sin to be excited about sex within marriage, or to look forward to sex in marriage before you’re married. Temptation becomes sin the moment you let the thought linger and let that little spark grow and catch fire. Remember David. He didn’t sin the instant he saw Bathsheba. He sinned when he didn’t turn away and kept looking, and from letting that quick glance grow into more. Fires only grow if their fed, thus, we must starve all the wrong fires in us. Because if we don’t, we’ll be burned. Proverbs 6:27 uses the imagery of fire to describe lust and desire, as it asks a blunt rhetorical question, “Can a man carry fire next to his chest and his clothes not be burned?” The answer is obvious.
I don’t want to be vague. Adultery in the modern world rarely starts with a motel room. It starts much smaller than that…with a glance, with a text, with a brief chat, with a private browser tab, with a DM that goes longer than it should, with friend requesting an old flame ‘just to see how they're doing’, with a growing relational closeness with a coworker that never gets around to talking about your spouse. None of these things feel like adultery while you’re caught up in them. But that’s exactly the danger. Jesus said it’s the heart that matters most in this, and we can be very inventive in the many ways we find to cross lines without actually getting physical. Thus, the seventh commandment invites us all to starve the wrong fires in us.
3) Feed the Right Fire
We’ve mentioned fire many times here today, how it’s a fitting image to use concerning adulterous desires. But let’s not be those who only employ the image negatively. Flip it around and see the positive side of it. Fire is a fitting image to use in discussing passion in marriage. So, if you’re married, do you realize God has given you a green light to enjoy your marriage bed? God designed marriage as a house, and sex so often works as the fireplace in that home, and when the fire is lit, it warms the whole home. Of course, each marriage is unique, having its own history, habits, and patterns…so I don’t think there is a one size fits all when it comes to how each marriage should throw logs into this fireplace, so I’ll just say this. God built this house called marriage, the fireplace was His idea, so enjoy it. To not do so, is to deny a great gift.
If you’re not married, remember, sex is not God, and it shouldn’t rule you or be master over you. There is more to your body than its reproductive organs, and more to your life than sex. Don't ask how you'll survive a year, or a decade, without it. Ask a better question instead: what fire can you fan into flame, or what can give yourself to, wholly and undivided, that a married person can’t? Paul says in 1 Cor. 7 the unmarried can devote themselves to the Lord with an attention marriage doesn’t permit. That doesn’t sound like a smaller life while you wait for a bigger one to start. It might just be the most fruitful fire you ever tend. A full and focused devotion to Jesus, split with no one. God may give you a spouse one day, and He may not. If He does, great. If He doesn’t, great. Either way we all must feed the right fires in us.
Now, whether you’re married or single, remember Galatians 6:7, you reap what you sow. Take the fire out of the fireplace, in any form, and it costs you more than you think. Keep it there, and it does exactly what it’s supposed to do. In other words, let God’s definition of sexual desire be your definition, and all manner of pleasant things will follow. Redefine sexual desire according to what you think is best, and all manner of awful things will follow.
Conclusion:
Church, each marital union in the world, is a shadow of something far greater. Paul says it plainly in Ephesians 5, that in a wife’s willing submission to her husband and a husband’s loving sacrificial headship to his wife, we see a beautiful picture of Christ and the Church. Paul says, “Now as the church submits to Christ, so also wives should submit in everything to their husbands. Husbands, love your wives, as Christ loved the church and gave Himself up for her, that He might sanctify her, having cleansed her by the washing of water with the Word, so that He might present the church to Himself in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish…This mystery is profound, and I am saying it refers to Christ and the Church” (Eph. 5:24-27, 32).
The reason the seventh commandment is so important is because marriage isn’t just a legal arrangement or some kind of emotional partnership. It’s a small picture of a strong Savior…who gave Himself for and ever loves His bride, the Church, no matter how many times she’s wandered.
Jesus is clear, there is an adulterous streak in every human heart, yet every Christian, married or single, is being pursued by a Groom who has never once let the fire go out on His side, no matter how many times we’ve built fires we shouldn’t have.
One day our Groom will return and the Marriage Supper of the Lamb will take place, and it’ll be a wedding feast like never before, one that never ends, where nothing threatens the fire of love between Christ and His Church.
In truth, every fire you’ve ever lit in the right place, and every fire you’ve ever lit in the wrong place, has been pointing to that fire all along.
So, as we wait for that great feast, the seventh commandment stands as an invitation to not only to guard the right kind of fire and to starve the wrong kind, but to point us to the best fire, which begins in Christ, grows in Christ, and lasts eternally in Christ.
[1] H.B. Charles Jr., Keeping Pleasure In Its Place, sermon on Exodus 20:14 – 3/11/25, accessed 9/19/26.
[2] Stephen Spinnenweber, Loving the Law: The Law of God in the Life of the Believer (Geanies House, Fearn, Ross-shire, UK: Christian Focus, 2025) 46.
[3] H.B. Charles Jr., ibid.
