There are five main teaching sections in Matthew’s gospel; these occur in chapters 5–7, 10, 13, 18, and 23–25. Some scholars suggest that these parallel the five books of Moses, and that therefore Jesus is portrayed as the new Moses, the final prophet who was to come.
It is certainly the case that Matthew wants to portray Jesus as the Davidic King, whose ministry began with the message: “Repent, for the kingdom of heaven is at hand” (Matt. 4:17). His gospel is the gospel of the kingdom; He has come to proclaim the rule of God in the lives of men.
Each November in the United Kingdom, when the new session of Parliament officially begins, the reigning monarch reads a speech outlining the policies that his or her government will pursue over the coming year. The “State Opening of Parliament” is carried out amid great pomp and ceremony. Essentially, it is the point at which the queen outlines how she will rule her kingdom through her Parliament for the ensuing year: the Queen’s Speech is a statement of intent, declaring her program.
In contrast, there is no pomp or ceremony in the Sermon on the Mount. But there is a statement of government here — in this great sermon, the King outlines how His kingdom will be identified and how God’s rule will be exercised in the lives of His subjects. It is, in other words, the formal inauguration of His kingdom: the King sets out His plan, the program by which His kingdom is identified and His rule administered.
Two recurring themes in Matthew run through this King’s speech. In Matthew 5:17, Jesus says, “I have not come to abolish [the Law and the Prophets]”; and in 5:22, 28, 32, 34, and 44, He uses the phrase: “But I say to you.”
These parallel themes help us to understand what Jesus is doing in the Sermon on the Mount. On the one hand, He is preserving, continuing, and fulfilling what God had previously revealed in the Old Testament. His function is not to “abolish” either the Law or the Prophets. Jesus recognizes Himself as standing in a stream of revelation, such that His teachings are of a piece with what the Old Testament declared. It is the same King who would govern His people now as then, and He brings His hearers back to the fundamental principles of morality that God revealed through Moses.
That does not mean that everything is to continue as it was before. By His fulfillment of the old law, some aspects of Old Testament legislation have been rendered obsolete. The sacrifices and ceremonies, for example, associated with redemption and atonement are done away with, precisely because Jesus came to fulfill them and to usher in perfect righteousness.
On the other hand, extracting the true meaning of Old Testament law means a break with the received rabbinical teaching of the day. So when Jesus says, “But I say to you,” He is not setting Himself against Moses but against those whose interpretations of the law have turned God’s covenant of grace into a covenant of works. For too many people, righteousness is a matter of obeying all the rules; Jesus actually teaches us that the rules require us to go deeper than the shallow religion of the rabbis might suggest.
Jesus illustrates this with reference to six practical issues. The first has to do with the meaning of the prohibition against murder (5:21–26). The commandment is clear: “you shall not murder.” The Pharisees and scribes understand this in its narrowest sense, believing that if they have never shed innocent blood, they have kept the commandment. But Jesus says that the commandment extends to “emotional murder,” to a sense of resentment and anger against someone. Such anger is itself a violation of man made in the image of God (5:23–24).
Human courts and earthly judges can weigh our actions externally — they can assess the evidence for what we have done and act accordingly. But Jesus digs deeper than this — He reminds His subjects that the standards of God go beyond external morality to the very thoughts and intentions of our hearts (Heb. 4:12). If we are angry, we run the risk not of being subject to human judgment but of being subject to God’s judgment. Anger must be dealt with if we are to please God: it is better to offend our brother by seeking reconciliation than to offend God by keeping the anger alive. We may never kill anyone, Jesus is reminding us, but unrestrained anger is a breach of the sixth commandment and can bring us to hell.
Kingdom living under the sovereignty of Jesus means living before God’s face, our hearts exposed to His all-seeing eye like an open book before Him. That is what God has always wanted from His people: that they would do justice, love kindness, and walk humbly with their God (Mic. 6:8). That is the religion that matters, not one that is based in external conformity to the letter of the Law, but one that conforms to the Law from a heart careful not to offend God. That is the ethic of the New Testament: we must put away what is earthly in us — “anger, wrath, malice, slander,” because you “have put on the new self, which is being renewed in knowledge after the image of its creator” (Col. 3:5–10). The standard of living Jesus requires is only the standard by which He lives Himself.