The acknowledged moral giants of Jesus’ day were the Pharisees and the teachers of the law. They made it their lifetime goal to study and obey the Scriptures. But Jesus has just said that the only people who can enter the kingdom of heaven are those who possess a righteousness surpassing the righteousness of these teachers.

From verse 5: 21 to the end of chapter he explains what a righteousness that “surpasses that of the Pharisees and the teachers of the law” is like. We need to think about these verses carefully, because there is no better treatment of the differences between these two kinds of righteousness anywhere else in the Bible, and we must have this better righteousness.

Our starting place is to understand that the contrasts in this section are not between Moses’ teaching and Jesus’ teaching, for Jesus has already stated his intention to uphold the Old Testament law.

What you think determines what you do.

The biggest bunch of hypocrites in the world are these social scientists who tell us what a person sees does not affect them. If that is so, my dear friend, why will somebody pay half million dollars for one minute of advertising in the Super Bowl? Would you pay 500,000 dollars for sixty seconds, if what people see does not affect what they do?

And Jesus knows that. And so our Lord here speaks about what happens on the inside.

Ethics of the Heart

Matthew 5:21–47 When Jesus quotes from the Old Testament, he says, “ “It was said” or “It has been said” (vv. 21, 27, 31, 33, 38, 43), indicating that what he is rejecting is not the Old Testament teaching but those human interpretations that had distorted it.

Just Behave Yourself

Matthew 5:27 You have heard that it was said by them of old time, You shall not commit adultery: 28 But I say to you, That whoever looks on a woman to lust after her has committed adultery with her already in his heart.

The descent to sin begins in the heart and mind.

Before you kill, unless in war or self-defense, there is usually some hate going on that brings on the killing. Like so, unfaithfulness in marriage begins in heart and mind.

Is adultery wrong?

Yes, Jesus teaches, physical involvement with someone of the opposite sex outside of marriage wrong? He is probing deeper into the meaning of this commandment, and what he is saying is that the root of the problem is in the impure desires of the heart. It is there, in the heart, where things begin to go radically wrong.

Jesus is teaching here since he explains himself in Matthew 18:7–9, where hands and eyes stand for “things that cause people to sin” (v. 7). So the meaning is this: Get rid of whatever is tempting you to sin.

What then does Jesus mean? Just this: we are to deal drastically with sin.

We must not pamper it, flirt with it, or enjoy nibbling a little of it around the edges. We are to hate it, crush it, dig it out. “Put to death, therefore, whatever belongs to your earthly nature: sexually immorality, impurity, lust, evil desires and greed, which is idolatry” (Colossians 3:5). Jesus in Matthew 5:29f. threatens with hell all those who will not deal drastically with sin.

Our generation treats sin lightly. Sin in our society is better thought of as aberration, or as illness.

It is to be treated, not condemned and repented of; and it must not be suppressed for fear of psychological damage.

Divorce and Remarriage

Matthew 5:31 It has been said, Whoever shall put away his wife, let him give her a writing of divorce:

The discussion of adultery and purity leads naturally to the question of divorce. The Jews of Jesus’ day had heard it said that the man who wants to divorce his wife must give her a certificate of divorce. The Old Testament passage to which appeal was made was Deuteronomy 24:1–4. The thrust of that passage is this: If a man finds some uncleanness in his wife and divorces her, giving her a certificate of divorce, and she then marries someone else who in time also divorces her, then her first husband cannot remarry her.

The only passage in the Old Testament to deal explicitly with divorce was Deuteronomy 24:1–4,

That passage does not teach divorce, though it recognizes that it happens, noting that husbands should give their wives formal divorce certificates to indicate they had renounced all claim to them. The point of the passage is that if a woman has been divorced by her husband, marries another man, and is then released from that marriage either by another divorce or by the second husband’s death, then she is not allowed to return to the first husband on the grounds that “she has been defiled.”

Here is what happened. In exactly the way people often function in moral areas today, the teachers of Christ’s time had become legalistic about the “certificate of divorce” but excessively liberal about what the husband was allowed to find “displeasing” or “indecent” in his wife. They ignored the matter of remarrying the first husband entirely.

Defining what was displeasing led to a well-known disagreement between the Rabbis Shammai and Hillel. Shammai was a conservative, and he interpreted the grounds of offense as adultery or sexual impurity in the woman. Hillel was a liberal, and he broadened the woman’s offense to include even so trivial matters as spoiling dinner, being troublesome or given to quarrels, or speaking disrespectfully of her husband’s parents. Given the nature of the human heart, it is easy to see which interpretation prevailed. Divorce was allowed for nearly anything.

Jesus sees the matter differently. Matthew 19:3–12,

And I say to you, Whoever shall put away his wife, except it be for fornication, and shall marry another, commits adultery: and whoever marries her which is put away does commit adultery. . What Jesus says is that God doesn’t like divorce at all—something the Pharisees could have discovered themselves from such texts as Malachi 2:16

Here, by means of a few simple words, Jesus discourages divorce, refutes the rabbinical misinterpretation of the law, reaffirms the law’s true meaning (cf. Matt. 5:17–18), censures the guilty party, defends the innocent, and throughout it all upholds the sacredness and inviolability of the marriage bond as ordained by God!

By Jesus’ day, this main principle was overlooked in favor of concentrating attention on the “uncleanness” which would make legitimate the first divorce. The particular expression for “uncleanness” is used only one other time in the Old Testament, where it refers to human defecation. What the sexual uncleanness is in Deuteronomy 24:1 is not clear; in any case it is, even in the Mosaic perspective, an exceptional thing. By Jesus’ day, however, some even taught that it could be some imperfection in the wife as trivial as serving her husband food accidentally burned.

The Creator said, Within this framework, therefore, it is obvious that if Moses permitted divorce for some gross uncleanness, it was an exception which found its rational in man’s hard, sinful heart.

Marriage is commitment;

And, far from backing out when the going gets rough, marriage partners are to sort out their difficulties in the light of Scripture. They are to hang in there, improving their relationship, working away at it, precisely because they have vowed before God and man to live together and love each other for better, for worse, for richer, for poorer, in sickness as in health, until death separates them. Love is the determined commitment to seek the other’s good, to cherish, shelter, nurture, edify, and show patience with one’s partner. And this commitment, worked out because of deep-rooted obedience to God, brings with it the emotional and sentimental aspects of love as well.

It is this high view of marriage which likewise underlies Jesus’ trenchant remarks on lust (5:27–30), and gives this block of material (5:27–32) its sanity. The Law and the Prophets, by Jesus’ own authority, point to the necessity of absolute purity and must not be trivialized by deceiving arguments which seek to escape that purity.

The great problem with marriage among the Jews in Jesus’ day was the ease with which so many men divorced their wives. How could this happen in a culture so deliberately based on the Bible and its standards? Or among a people known for being so centered on the family? The answer is what we have been noting all along: the perversion of the heart. In the case of divorce it worked like this.

Just Tell the Truth

Matthew 5:33 “Again, you have heard that it was said to the people long ago, ‘Do not break your oath, but keep the oaths you have made to the Lord.’ 34 But I tell you, Do not swear at all: either by heaven, for it is God’s throne; 35 or by the earth, for it is his footstool; or by Jerusalem, for it is the city of the Great King. 36 And do not swear by your head, for you cannot make even one hair white or black. 37 Simply let your ‘Yes’ be ‘Yes,’ and your ‘No,’ ‘No’; anything beyond this comes from the evil one.

“Do not break your oath” alludes to Leviticus 19:12 and Numbers 30:2 and would more commonly be translated “do not swear falsely” or “do not perjure yourself.” To “swear” does not mean to curse or use bad words but to affirm the truth of a statement while calling on God to judge oneself if it is in fact untrue.

Jesus declares that it would be best to avoid oaths altogether. The situation described is one in which many Jews viewed swearing by “heaven,” “earth,” “Jerusalem,” or “one’s head” as less binding than swearing “by God.” Jesus stresses that each of these items belongs to God in an important way (cf. Isa 66:1) so that the conventional Jewish distinctions are false. Jesus’ followers should be people whose words are so characterized by integrity that others need no formal assurance of their truthfulness in order to trust them.

What was the problem in Jesus’ day with oaths?

It was exactly what we have been seeing all along: the corruption of the heart.

People knew they were to keep their word, as we do. Above all, they knew if they had taken an oath they were to keep it. But the rabbis focused on the specific wording of the oath, distinguishing between those that were binding and those that were not. If the Bible said, “Keep the oaths you have made to the Lord,” such oaths were clearly binding. But what about oaths that were made only “to heaven” or “by the temple” or “by one’s life”? Were such oaths binding? An entire tractate of the Mishnah (Shebuoth) is given to distinguishing between oaths that had to be kept and those that did not. Jesus makes it clear,any failure to keep one’s word is a sin before God. So, for the righteous man there should be no need for oaths at all. On the contrary, a righteous man’s yes should be yes, and his no should be no.

These verses do not forbid oaths under formal occasions, as in a court of law, since the Bible contains examples of such oaths (see Rom. 1:9; 2 Cor. 1:23; Phil. 1:8; 1 Thess. 2:5, 10). Even God takes oaths (Heb. 6:17–19).

Always Seek Perfection

Matthew 5:48 Be you therefore perfect, even as your Father which is in heaven is perfect.

Jesus is not frustrating his hearers with an unachievable ideal but challenging them to grow in obedience to God’s will—to become more like him. J. Walvoord rightly observes, “While sinless perfection is impossible, godliness, in its biblical concept, is attainable.”

But such godliness cannot be comprehensively formulated in a set of rules; the ethics of the sermon are suggestive, not exhaustive.

It is true that we will never be perfect in this life, but the perfections outlined in this sermon are still those for which we should aim and that we should increasingly attain by God’s grace and power in our lives. The form of verse 48 is exactly the same as Leviticus 19:2, with “holy” merely being displaced by “perfect” (“Be holy because I, the Lord your God, am holy”), and that Leviticus 19:2 is likewise urged on God’s people in the Bible.

Jesus is saying that the “direction in which the law has always pointed is not toward mere judicial restraints, concessions arising out of the hardness of men’s hearts, still less casuistry perversions, nor even to the ‘law of love. Instead, it pointed rather to all the perfection of God, exemplified by the authoritative interpretation of the law bound up in the preceding contrast. This perfection Jesus’ disciples must emulate if they are truly followers of him who fulfills the Law and the Prophets.