If your trust is in Christ, you are united to him by faith. You have died with him and been raised with him. You are a new creation. Does that mean that you have conquered temptation and can check off the Seventh Commandment as one that you have kept? Look at what Jesus says in Matthew 5:27–30. How can you be pure in Christ in an impure world? How can you be pure in Christ when you struggle with purity in your own heart?
Beware of adultery of the eyes and heart. Your sin starts in your heart. Jesus introduces “You shall not commit adultery,” with the phrase he uses for each of these examples, “You have heard it said.” He is certainly not abrogating the commandment, for what he goes on to say affirms the sinfulness of adultery. Jesus makes explicit what the Old Testament taught, but which the leaders of Israel tended to ignore—adultery begins inwardly. You see it in the 10th Commandment and in 2 Samuel 11, when David on his palace roof sees and begins to desire another man’s wife—leading to a whole complex of sins. Sin is easy to fall into, but extracting yourself is difficult. The teachers in Israel had check box mentality: if I have not gone to bed with my neighbor’s wife, I’ve kept that commandment. Jesus wants you to realize that the righteousness of the kingdom of heaven requires more. He doesn’t want you to underestimate the power of temptation. He knows what it is like. He was conceived and born with a truly human nature. Unlike the rest of us sons of Adam and daughters of Eve, whose nature is corrupt, his will was sinless. But, as Hebrews reminds you, he was tempted like we are. He was a red-blooded Jewish teenager—and remained sinless. Sin starts inwardly, and unless rooted out by God’s grace and the power of his Spirit, grows there, and develops into something ugly. “Every unclean thought or glance would be adultery if it could, every covetous desire would be oppression, every thought of unbelief would be atheism, might it grow to its head [that is, ‘ultimate outcome’].” (John Owen, Overcoming Sin & Temptation, edited by Kapic and Taylor, p. 53).
This rebellious world pushes temptation at you. In Romans 1 Paul makes the point that sexual immorality (which can be both a sin for which God punishes and can be part of the punishment itself) involves worshiping and serving the creature rather than the Creator, who is blessed forever. We live in a culture in which the ultimate good is gratifying one’s desires. And we have come to expect instant gratification. We believe that we have the right to make ourselves in whatever way we want. In our culture sex sells—everything from toothpaste to cars. Porn, and even “mommy porn” is readily available at the click of a mouse. Relationships have been utterly cheapened. The church has been more influenced by our culture than we care to admit. Christian families and even Evangelical churches have been relatively unsuccessful at communicating a biblical ethic to young people. We need to frank where the Bible is frank. We need to communicate. And we need something more than warmed-over version of the health and wealth gospel. We need to understand who God is and who we are.
Recognize that sex is God’s good gift! God established the first marriage in Eden—before the fall. Contrary to a popular lie, the Bible does not consider sex dirty or evil. God created mankind, male and female in his image. That makes us different from animals. (And when God’s commandment for purity is broken, it involves a sin both against God and against someone who is image of God.) In Genesis 2, after God pronounced his creation “very good,” he said, “It is not good for man to be alone,” and created Eve. The first marriage was between two sinless people in the Garden of Eden. God created us with strong sexual desires—and gave us the place for those desires to come to full expression. There are few things in this world more beautiful than married love, whether it is the glow of couple who have been married for two weeks or the quiet contentment of a couple still holding hands when they’ve been married for more than half a century. There are few things more ugly than the abuse of sexual relations. Understanding who you are as image of God can be crucial to living a life that glorifies God.
Marriage points beyond itself to Christ. As important as marriage is, it is not our ultimate goal. Our marriages exist to glorify God, and he must be central in them. Throughout the Old Testament God repeatedly describes himself as the husband of his people. Idolatry is spiritual adultery. In the New Testament Christ is revealed as the one redeeming and purifying his people as beautiful bride. “God did not fish around for some image to use to show his people what his love is like, and then stumble on marriage as the best one to convince them to return to him in covenant devotion. . . . No. God planned it the other way around. He placed in us at creation deep sexual emotions so that we might understand the jealousy of his love for us and the joy of jealousy for him.” (Edmund P. Clowney, How Jesus Transforms the Ten Commandments, p. 95).
You are pure in Christ. You have been washed—by the Spirit of our God. Picture yourself standing before the throne on the day of judgment. Were Christ to ask, “Have you kept the Seventh Commandment?”would yon not have to admit, together with the rest of God’s people, “No, I have not.” Where are those people today? In the church. In 1 Corinthians 6:9–11 Paul lists the backgrounds of some in that church, and adds, “But you were washed, but you were sanctified, but you were justified.” We are all people with a past. But Christ died and rose so that your sins against this commandment and others are forgiven. And by his Spirit he is busy working in your life.
Do battle with temptation. Jesus uses graphic language as he describes how strongly you need to battle against this sin. He is not teaching self-mutilation (an one-eyed person can still look lustfully). Bill Elder quotes a former pastor as saying, sin requires radical surgery. “Be killing sin or it will be killing you.” (John Owen, Works 6:9). Repentance involves turning away from sin. The righteousness of the kingdom of heaven starts with the Spirit’s work in the heart and continues to action in all areas of life. “In Matthew 5:27–30, Christ charges that the teachers of the law put the boundaries of purity in the wrong place, at the edge of behavior, misunderstanding the law’s intent. Christ placed the boundaries squarely within the heart. That was the original intent of the law.” (Paul David Tripp, “Teens & Sex: How Should We Teach Them?” p. 19). Put to death the deeds of the flesh.
Look forward to the glorious wedding feast of the Lamb. Look at what Christ is presently doing in his church (in you), Ephesians 5:25–33. Look forward to what you will be in glory, Revelation 21:1–4; 19:6–9, and let that shape your life today.
The righteousness of the kingdom of heaven involves asking God’s forgiveness, finding you purity in Christ, and then living to his glory.