You shall not commit adultery.
Sex within marriage is wholly good. It is God’s gift to every married couple. But sex is powerful. It is not just the merger of two bodies, but the merger of two souls. When sex is treated casually and promiscuously, then great damage is done. People are hurt. Marriages are wrecked. Families are destroyed.
Our culture may minimize adultery, and Hollywood may even glamorize it, but down deep every person knows instinctively that adultery is wrong and a terrible betrayal of the love, commitment and loyalty of marriage.
So God gives us the seventh commandment for our good. He gives us the commandment for our protection, to protect us from the pain, hurt and destruction of adultery.
In the Sermon on the Mount, Jesus quotes this commandment and gives the true spirit of it: “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 teaching us that the seventh commandment precludes not just physical adultery, but also heart adultery. Don’t look at other people as objects to be used, but as persons to be loved.
This does not mean it is wrong to notice attractive members of the opposite sex. That’s not lust, but the normal response of a human being. Lust comes when we go beyond that and begin to fantasize about having sex. Then it becomes a violation of the seventh commandment.
One more issue: How can we avoid adultery and stay faithful to God and, if married, stay faithful to our spouse? Three brief suggestions.
First, give constant priority attention to your marriage. Work on your marriage and never take it for granted.
Second, guard friendships with the opposite sex. Don’t be reckless. Decide in advance on appropriate boundaries and guidelines.
Third, draw close to Jesus. Fall in love with Jesus. Find all your satisfaction in the one who alone can fill the human heart.