The eight beatitudes that begin the Sermon on the Mount are probably its best-known portion, with the possible exception of the Golden Rule found in Matthew 7:12. But in a sense, they are only the introduction, describing the kind of people the rest of the sermon is for. The main body of the sermon actually begins with verse 17 of chapter 5, and it continues to verse 12 of chapter 7, the verses marked off by what scholars call an inclusio, meaning a repetition of words that both begin and end a section, serving a bit like an envelope or a wrap for what comes in between.
The words “the Law and the Prophets” are the inclusio for this section. They introduce it in 5.17 (“Do not think that I have come to abolish the Law or the Prophets”), and they end it in 7:12, the statement of the Golden Rule I just referred to (“So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets”).
When Jesus starts by saying, “Do not think that I have come to abolish the Law or the Prophets,” He is referring to misunderstandings concerning His teaching that had developed in the early days of His Galilean ministry. D. A. Carson does not want to make too much of this beginning. He says that the words are not to be understood “as the refutation of some well-entrenched and clearly defined position,” only “as a teaching device Jesus used to clarify certain aspects of the kingdom.” But the Gospel does contain suggestions of some things that might have led to misunderstandings and criticisms in this area.
For example, a few chapters after the conclusion of the Sermon on the Mount, the disciples of John the Baptist come to Jesus with a question that indicates he was perceived as less demanding in his piety than either John or the Pharisees: “How is it that we and the Pharisees fast, but your disciples do not fast?” Again, an implied criticism seems to exist in the contrast people were making between Jesus and John the Baptist: “John came neither eating nor drinking.… The Son of Man came eating and drinking, and they say, ‘Here is a glutton and a drunkard, a friend of tax collectors and “sinners.’” Tax collectors and “sinners” were judged as breakers of God’s law.
Most significantly, Jesus was thought to favor sinning on the Sabbath. When the disciples picked heads of grain on the Sabbath and ate them, the observing Pharisees said, “Look! Your disciples are doing what is unlawful on the Sabbath.” At other times they objected to His healing on the Sabbath. In one way or another, each of the Gospels indicates that controversy over the Sabbath was the initial reason for the hostility of the leaders toward Jesus that led at last to His arrest and crucifixion.
What Jesus insists on here is that He had not come to “abolish” the Law or the Prophets but to “fulfill” them (v.17). In what sense was this true? What did Jesus actually mean? If we look at the big picture, we have to acknowledge that His death certainly abolished the Old Testament sacrificial system. And there were other things Jesus set aside, such as the Jews’ strict laws of kosher. In what sense did Jesus come not to abolish but to fulfill the Old Testament?
First, Jesus came to fulfill the law’s moral demands. Some understand v.17 as Christ’s claim that He came to fulfill the law’s moral demands. Jesus did this perfectly, of course. He was sinless. He could even ask his enemies, “Can any of you prove me guilty of sin?” and leave them speechless (Jn.8.46). But while it is true that Jesus fulfilled the moral demands of God’s law, to understand “fulfill” in this way is out of place in this context. The issue in this paragraph is not how Jesus lived but what He was teaching. Were His teachings contrary to the Old Testament?
Second, Jesus completed the law’s inadequate teaching with His teaching. Some who understand that this verse is about the teachings of Jesus take it to mean that Jesus was fulfilling the law by completing it, that is, by adding to or rounding out what was already found in the Old Testament. The problem with this view is that Jesus seems to be doing the exact opposite in this paragraph, not for a moment suggesting anything about the incompleteness or inadequacy of the law but rather insisting on its perfection and abiding validity (v.18). Jesus added to the Old Testament writings, of course. We have a New Testament now also. But that is not what Jesus is dealing with in these verses.
Third, Christ himself is the fulfillment of the law. The best explanation is that we should understand “fulfill” in the same sense it had earlier, when it was used of Old Testament prophecies that were fulfilled by Jesus’ coming: Mt.1.22; 2.15,17; 4.14, for example. This means that the Bible is about Jesus and that He is its fulfillment in all ways. He fulfills the moral law by His obedience, the prophecies by the specifics of life, and the sacrificial system by His once-and-for-all atonement. This is a part of what Paul means in Romans 10.4 when he calls Christ “the end of the law.”
This is how D. A. Carson sees it: “The best interpretation of these … verses say that Jesus fulfills the Law and the Prophets in that they point to Him, and He is their fulfillment. The antithesis is not between ‘abolish’ and ‘keep’ but between ‘abolish’ and ‘fulfill.’” Jesus is thus “not primarily engaged … in extending, annulling or intensifying the OT law, but in showing the direction in which it points.”