In this seventh commandment the Lord tells us how important marriage is to him, and what he wants us to do to protect it. ‘You shall not commit adultery.’
He means that if someone is married, they shouldn’t have a sexual relationship with anyone else. Sex is not a way of having a casual relationship, or excitement, or doing whatever you feel like. It’s for marriage.
Does this sound as though God is only interested in restricting our freedom? This opinion is commonly held, so, it’s important to remember the events from which these commands arise.
The Lord has saved Israel from slavery. He’s leading them to a land of their own. He calls them his ‘special possession’. By favouring them, he is revealing himself to many others as well. There’s already been 19 chapters of Exodus to tell this story before we get to the commands in chapter 20.
If you don’t have this narrative—and then the fascinating story that follows, right up until God’s Son comes to earth—these commands may be hard to understand.
Commands work properly when they are part of a story of how everything fits together. In fact, if you don’t want’ God’s story. you need to write another narrative to fit the way you want to live.
For example, these other narratives may say that our being alive is simply a matter of chance, that commands are the way we become victims of power plays, or that we must decide for ourselves who we are and what is right for us to do. A lot of work goes in to building up these story lines.
Then, these narratives lead to commands—just as certainly as the Lord’s story does. Just listen to the daily news! We have to make sure other people conform to our story line so that our freedom is secured and we can arrive at the land we have imagined.
However, if these narratives have not researched what God has said to the world, and what he has promised and what he has done, they are not based on all the available information. On the other hand, if we believe our Creator is kind and generous and that he has sent his Son to live among us, we can follow through what his command about marriage means. So, that’s what I’ll do!
There’s nothing new about a man and a woman meeting and marrying. It’s been with us from the beginning (see Genesis 2:18-25). God makes a man, and says it’s not good for him to be alone. So, he makes a woman—a creature like him but opposite to him. He brings her to the man. Only then can they take up their responsibility to look after the creation.
In this creation story, there’s a line of explanation about all subsequent marriages: ‘For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh’ (Genesis 2:24). That is, before they express their love physically, they need to leave one family to create another one, and be faithful to the one who is like but different. Then, they become one flesh by sexual union (1 Cor. 6:16).
The dynamics of people sharing a sexual relationship is so profound that the only place it ought to happen is when a man and a woman say to each other, “I’m going to belong to you and care for you as long as we both live.’ That is what sex is expressing. And marriage is what enables sex to be a power for good rather than a power to pollute and destroy.
And this is what the Lord is now protecting by his command.
It’s not surprising that God makes so much of this. He is creating a community to be close to him, and to be cared for by him. Jesus Christ comes to take this church as his bride (Eph. 5: 25-31).
Marriage between a man and a woman is a covenant like God’s covenant with us. It represents this God-relationship in a human-to-human relationship. And because children are born into this union, they can grow up in an environment of faithful love. This is how they learn to be human beings.
You may say this is all idealistic. Not really. An ideal is an idea we turn into a doctrine—something we create. But marriage is something God creates. It’s not an idea. It’s how things are.
If you are married, there’s something you share with that person that you can’t share with anyone else—sexual union, and all the intimacy that goes with that.
Sex is not OK if you are steady with your girlfriend or boyfriend. It’s not OK if you feel deeply about each other. Your body’s not your own to do what you like with. It needs to be kept for the person you may marry one day. This is the way it is spelled out for young people in the book of Proverbs (Prov. 5:15-21).
Clearly, sexual interest is strong when we are young. God made us this way. However, the fact that our community makes so much of sex doesn’t encourage restraint, so we need to be prepared to be different. And waiting won’t do us any damage—even though it may feel like it sometimes! In fact, it will give us character, and purity to give to the one we want to spend our life with.
Outside of marriage, sex makes increasing demands. Because it’s not ‘the real thing’—that is, an expression of married love—it needs increasing doses, like a drug (Mark 7:20-23). It leads to other kinds of dissipation as well (Galatians 5:19-21)—even community violence.
For generations, our culture has encouraged free sexual expression. But it hasn’t encouraged the best in our humanity. It hasn’t led to happiness. Just look at the number of court cases going on at present over this issue. It hasn’t led to greater creativity and energy. Rather, it leads to dissipation. There’s a dynamic or energy in sex that needs marriage for it to be a power for good rather than a power for evil.
The way Jesus spells this out makes the matter even clearer (Matt. 5:27-28; 19:8-9). He says, ‘You have heard that it was said, “Do not commit adultery.” But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart’ (Matthew 5:28). He goes on to show the lengths we should go to if we are going to avoid sinning with our eyes or our hands.
Paul spells out how careful we need to be with our morality at this point (Ephesians 5:3-7). Effectively, he says, you can’t be a Christian and mess around with your sexual life.
What happens if you’ve been living without this perspective? What if, very deeply, your life is now shaped and soiled by breaking God’s command? Here’s where the difference between God’s story and the story we write for ourselves matters a lot. The stories we write can’t invent a redeemer. But God sends one.
This is why we love Christ so much. He takes to himself all the pollution we gather about ourselves by breaking his commands. He bears God’s judgement on it. And he rises from the dead and says to you and me, ‘You are clean again!’ Whatever has happened in the past, you can be live as someone who is clean, and ready for real marriage. This leaves many current issues unaddressed—things like gender fluidity and homosexuality. But if we understand how God made us, the command he has given us, and the redemption he has accomplished, we will know that sex is for marriage between a man and a woman, and not for anything else. All the other things we discuss need to take this as their starting point.