TEXT: Matthew 5:27-30

SUBJECT: Exposition of the Sermon on the Mount #6: Adultery in the Heart

Tonight brings us to the sixth paragraph in our Lord's great Sermon. The present subject is introduced in v.17: "...I came not to destroy the Law or the Prophets, but to fulfill". He's not draining the Old Testament, but filling it to the brim.

He began with the subject of murder. Moses prohibited the act; the Lord Jesus forbids the bad attitudes that lie behind it. Which ones? Anger, contempt, and malice. We mustn't kill others, of course. But neither may we lash out at them, look down on them, or wish them ill.

Next, He takes up the sin of adultery.

"You have heard that it was said to those of old, v.27: `You shall not commit adultery'..." Had they "heard" this? Yes they had; they all had. Where did they hear it? They heard it from Moses. It was taken verbatim from the 10 Commandments.

What did it mean as originally given? It meant this: You must not take another person's spouse. The best known example is David and Bathsheba. She was the wife of Uriah the Hittite, one of the king's most loyal men. Late one afternoon, David was relaxing on his balcony and spotted the beauty bathing down below. He asked her up, got her consent, and knew her carnally. The king--who had a harem full of women--committed adultery by taking another man's wife.

Its punishment was death, Leviticus 20:10: "The man who commits adultery with another man's wife, he who commits adultery with his neighbor's wife, the adulterer and the adulteress, shall surely be put to death".

This was the sin of which the Canaanites were especially guilty--and the sin which would make the land "vomit up" the people of God as well.

"You have heard that it was said, `You shall not commit adultery'".

"But I say to you, whoever looks at a woman to lust after her in his heart has already committed adultery with her in his heart", v.28.

Moses prohibited the act of taking another person's spouse; the Lord Jesus forbids the desire that lies behind it. He calls it "lust". This means "to want badly". It's not the passing impure thought He equates with adultery, but the fixed desire for a person you cannot have or the general desire of wanting any/every attractive person. Peter describes the craving as "eyes full of adultery".

In extreme cases, the lust can become an obsession. You can't get the woman out of your mind.

But more often, it's an occasional fantasy. You don't intend to act on it. It may be impossible. Yet you're not quite willing to give it up, either. When the desire is entertained, it becomes adultery. In our world, it's very hard to keep lewd and provocative images out of your mind. You're bombarded with them day and night. But, in the words of Billy Bray:

"You can't keep the birds

from flying overhead;

But you can keep them

from nesting in your hair!"

The Lord Jesus identifies lust with adultery--the desire for someone with actually having her. It is not like adultery. It is adultery. Therefore, we must avoid both the act and the desire.

How can we do this? The Lord tells us in vv.29-30: "And if your right eye causes you to sin, pluck it out and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell. And if your right hand causes you to sin, cut it off and cast it from you; for it is more profitable for you that one of your members perish, that for your whole body to be cast into hell".

Before we interpret the Lord's saying, notice what He doesn't say: He doesn't provide a list of rules. Why not? Because what excites one person to sexual lust leaves another unaffected. Some men can go to the beach without guilt; others should move to Kansas! Lust is triggered by mental associations which are unique to every person. It could be a perfume; it could be a song; it could be a full moon. Hence, we must be very reluctant to make up rules for others to keep, or to pass judgment on them if they don't.

If you want to avoid sexual lust, you must "pluck out right eyes" and "cut off right hands". What does this mean? Origin (d.254) took it literally, and castrated himself. Is this what the Lord means? It isn't. Why not? Because lust is not in the testes, but "in the heart" (i.e., mind). And so, Origin was wrong. He didn't lower his lust, but only raised his voice!

What does it mean? This: Do whatever is necessary to avoid sexual lust. Why? Because you'll either give up sexual lust--or you'll go to hell. This is the plain meaning of the text. Which is better? To go to heaven with one hand or go to hell with two? To go to heaven with one eye or go to hell with two? The answer is implied in the question. Of course, it's better to go to heaven maimed than to go to hell in perfect shape.

In the same way, it is better to inconvenience yourself in avoiding lust than to take the easy way and be damned for it. What sort of sacrifices must we make in order to shun this "adultery of the heart"?

Whatever is takes. This will differ from person to person. But the following guidelines are true for all.

"Whoever looks at a woman with lust in his heart has committed adultery with her already in his heart".

If these words are true (and they are), we are all guilty before God. And in need of His grace. Let us seek it in forgiveness and renewal. God help us, for Christ's sake. Amen.