This is part of a 10 Commandment series.
You can find the previous 6 below:
Commandment 1
Commandment 2
Commandment 3
Commandment 4
Commandment 5
Commandment 6

One of the beautiful truths about the Ten Commandments is that these rules transcend culture and history. It doesn’t matter where you live in the world, murder is always forbidden. You’re not going to find many places where stealing is celebrated. No one appreciates a liar. And for our purposes in this article, adultery is always wrong. Even in our modern-day American culture, filled with every kind of sexual perversion, adultery is frowned upon.

The reason this fascinates me is because by and large, we live among people who have rejected God. They have no standard or basis to determine right and wrong. The unbeliever has zero justification to establish absolute morality. And yet, ask any married couple, and they’d tell you, they value fidelity. This is because “the work of the law is written on their hearts” (Romans 2:15).

God’s law upon every man’s heart is also what we would call the conscience. The human conscience is one of the greatest proofs that the God of the Bible is true. Every man is governed by God’s law in his conscience, and this is why sins like adultery are considered immoral even by people who cannot give sound reasoning for moral claims.

What is Adultery?

Before we move on any further, let’s define our terms. What is adultery? Contemporary dictionary definitions match the biblical understanding of the term. Adultery is when a married person (male or female) has voluntary sexual relations with a person who is not his or her spouse.

If Sue is married to Al, but Sue decides to have sex with Bob, Sue commits adultery. In fact, biblically speaking, Bob  becomes an adulterer too, not just Sue. “If a man (Bob) is found lying with the wife (Sue) of another man (Al), both of them (Bob and Sue) shall die, the man who lay with the woman, and the woman. So you shall purge the evil from Israel” (Deuteronomy 22:22, names added by myself). In our day, I am convinced many would say that adultery can only be committed if you’re married, but that’s not true. Scripture considers both the married person and the unmarried person guilty of adultery if sexual intercourse takes place the way described above.

Scripture also makes a distinction between fornication and adultery. Adultery is explicitly when a married person has sexual relations with someone who is not his or her spouse. Fornication is any sexual relationship outside the marriage covenant between a man and a woman. This could be pre-marital sex, adultery, or homosexuality. You could say all adultery is fornication, but not all fornication is adultery. Nevertheless, Scripture condemns both.

Why does the Lord forbid Adultery?

This may seem obvious, but we need to ask the question: why does the Lord forbid adultery? Is He keeping us from enjoying the fullness of the human sexual experience? Or is the Lord acting like a loving Father and protecting us from harm? I hope you see that the latter is true.

Imagine that a man built his son a Go-Kart track in their backyard equipped with incredible turns, multiple lanes, several cars, and a finish line. His only rule was that his son does not exceed thirty miles per hour. Is the father trying to take away from the son’s joy or is he trying to increase his son’s happiness by protecting him with this rule? The father desires his son’s happiness. He knows that if his son goes too fast, he will either crash and hurt himself or tear up the track where it can’t be used anymore. The rule is designed so the son can enjoy the gift his father gave him.

Arguably the greatest earthly gift God gives to his image bearers is family. Personally speaking, I love being a husband and father. I love spending with with my family. I love providing, protecting, and leading. Adultery would shatter my family. It would be like the little kid running his Go-Kart into the wall traveling one hundred miles per hour. If I cheated on my wife, I would lose her trust and possibly our marriage through divorce. If separation happened, we would have to live in different homes and share custody of our daughter. As a pastor, I would lose my job and ministry career. The trust and good reputation I have built over the last 17 years would be gone overnight—all because I chose to step outside my marriage for a few moments of pleasure. It’s not worth it. “He who commits adultery lacks sense; he who does it destroys himself” (Proverbs 6:32).

The Lord forbids adultery because it shatters families. But adultery can also shipwreck a person’s faith. Proverbs chapter seven is one of Scripture’s most ominous warnings against fornication and adultery. It pictures a “young man who lacks sense.” Solomon sees him walking down the road, passing by the adulteress’s house. She’s waiting for him. Her husband won’t be home for a long time, and she’s laid the sexual trap for this young man. Before he knows it, she grabs and kisses him, and he becomes intoxicated by her fragrance and beauty.

With much seductive speech she persuades him;
with her smooth talk she compels him.
All at once he follows her,
as an ox goes to the slaughter,
or as a stag is caught fast
till an arrow pierces its liver;
as a bird rushes into a snare;
he does not know that it will cost him his life.
(Proverbs 7:21-23)

What’s interesting is that she’s the married person in the story, but it’s the young man who wrecks his life. Adultery wouldn’t kill him physically. But it will cost him spiritually. The Bible says adulterers do not have the Spirit of God (Gal 5:19- 20) and will not inherit the Kingdom of Heaven (1 Cor. 6:19-20).

Uprooting Adultery

If we’re going to solve the problem of adultery, we cannot focus merely on the act itself. We must get to the root of the issue. Let’s probe into this story.

Why did the man walk by the home of the adulteress woman? Clearly, they knew one another. She knew he was coming. He knew she was married, but he did it anyway. What would cause a man and a woman to commit such sins? The answer is always found in the heart. And its core, adultery is founded upon lust.

“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 is not redefining the Law of Moses. He’s giving the full sense of it. The religious leaders reduced every Law to the external. Adultery, then, was only when the physical act occurred. Jesus, however, says that adultery begins in the heart. Lust gives birth to action. Therefore, the heart is the battleground and where the root of sin must be killed.

According to our Lord, we must go to whatever lengths necessary to kill this sin. “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” (Matthew 5:29-30). The command is metaphorical. Jesus doesn’t want us to literally mutilate ourselves. His point is that we must be willing to do whatever it takes to avoid and kill sexual sin. Do whatever is necessary to not commit adultery. Maybe that means you quit your job to get away from a certain co-worker. Perhaps you need to get offline to avoid social media contacts. Some people need to make the decision the man in Proverbs didn’t make and take a different route home at night. Do whatever it takes, because, though the commands are metaphorical, the threat is not. Adulterers will not inherit the Kingdom (1 Corinthians 6:9-11). Because of the seriousness of the sin of adultery, Jesus’ promises to throw them into Hell.  Adultery may provide a few moments of gratification, but it also may cost you your life.

Brandon is the Associate Pastor of The Journey Church in Lebanon, TN and leads the Recovery & Redemption ministry for the church. Brandon is married to Sherrie and has a daugher, Emma.