17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. 18 For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished. 19 Therefore whoever relaxes one of the least of these commandments and teaches others to do the same will be called least in the kingdom of heaven, but whoever does them and teaches them will be called great in the kingdom of heaven. 20 For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven.
The structure of Jesus’ Sermon on the Mount is beautiful. It begins in the first 12 verses of Matthew 5 with the Beatitudes, which gives us a remarkable description of the powers of Christ’s Kingdom. Next, in verses 13-16, the Lord gives two brilliant metaphors to describe the overall effect of these Kingdom powers in a hostile world – salt and light.
Then in verses 17-20, Jesus gives a summary description of the righteousness of his Kingdom, introducing six examples of how this righteousness is a continuation of the Mosaic Law. He introduces each example with a variation of this formula: “You [y’all] have heard that it was said… but I tell you [y’all]….” Each of these three sections of his sermon are increasingly personal. The beatitudes speak in the third person. But in the final beatitude and, in the metaphors, we saw last week he switches to the second person (Blessed are y’all). In the applications that follow, he switches to the third person (I tell you).
No rabbi or scribe had ever spoken like this. They spoke in the second or third person. They would quote a rabbi who was quoting a rabbi who was quoting a rabbi. Jesus’ style of preaching is radically personal and authoritative. It was upside down from the religious conventions of his day. Only God had the authority to say, “I tell you all….”
In verses 17-20, Jesus relates his Kingdom to the Old Testament Law. Verses 17 and 18 speak of the radical righteousness of Christ and the Law. Verses 19 and 20 speak to the radical righteousness of the citizens of his Kingdom and the Law. It is a call to strive for thorough righteousness in a dark world that is dead meat.
JESUS AND THE LAW
After presenting the gifts and powers of his Kingdom and applying the two metaphors, it’s possible Jesus sensed some of his listeners thought he was abandoning the law of the Old Testament. He has mostly been telling his listeners what they already are through their faith union with him. Up to this point in his sermon, Jesus has said nothing about the importance of keeping the law. He has said nothing about the traditional interpretations of the law, and the importance of observing them.
He has told them very little of what to do. To correct any misunderstanding, Jesus gives a very powerful disclaimer:
17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. 18 For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished.
What is the law? The first five books of the Old Testament are known collectively as “the law” in distinction from “the profits” (Lk. 16:16). More generally in scripture, the words for law both in Hebrew and in Greek can mean a wide variety of things: commandment, principle, instruction, and so on. So, the meaning of the word “law” can be determined only by examining its use in each context.
So how does Jesus frame the context of the law? He uses the common distinction between the law and the prophets (v. 17). He speaks about the law in terms of its commands (v. 19). Jesus is referring particularly to the concept of the law as the specific commandments God has given to his people to regulate their entire lives – moral, religious, social, and political. Jesus is speaking of the law in this sermon as the commandments God gave to his people through the ministry of Moses.
This relationship between Christ, the citizens of his Kingdom, and the law has been drastically misunderstood by more than simply the Pharisees who were listening to Jesus at that time. The 2nd century heretic Marcion rewrote the New Testament by eliminating any reference to Old Testament passages. He actually removed the Sermon on the Mount from his version of the Bible. Some of his later disciples reinserted this sermon but changed the wording to suit their views.
Two centuries later, Saint Augustine found himself embroiled in a battle with another heretical group, the Manicheans. They also repudiated the Old Testament and its “vengeful” God. Augustine argued that Jesus was not abolishing the law. Rather, he was correcting the perversions that the scribes and Pharisees had made of it. Augustine’s teaching remained the standard among the church fathers and through the Dark Ages. The reformers maintained the same position.
Martin Luther repeatedly stated that the true interpretation of the law had been obscured by the rabbis. Calvin argued the same, that Christ was restoring the true nature and purpose of God’s law that had been obscured by centuries of falsehood through the leaven of the Pharisees and scribes. What Jesus criticizes is not God’s holy law itself but the contemporary formulations of the law.
Christ’s perfectly-lived, law-keeping life and blood-shedding death ended the requirements of the ceremonial laws, such as animal sacrifices and dietary restrictions. Paul devotes an entire letter, written to the congregations of Rome, on this subject of Christ and the law. He summarizes the question of salvation by Christ alone through grace alone: “Do we then, nullify the law by this faith? Not at all! Rather, we uphold the law” (Rom. 3:4). Later in the letter he becomes even more specific:
For God has done what the law, weakened by the flesh, could not do. By sending his own Son in the likeness of sinful flesh and for sin, he condemned sin in the flesh, 4 in order that the righteous requirement of the law might be fulfilled in us, who walk not according to the flesh but according to the Spirit.
If you have read Matthew’s gospel before, then you may already be familiar with the way in which Jesus fulfills the prophets. The beginning chapters emphasize fulfillment: “all of this took place to fulfill what the Lord had said through the prophet” (Matt. 1:22; 2:6, 15, 17, 23; 4:14). Matthew’s gospel account is all about Christ and his Kingdom fulfilling the entirety of the Old Testament.
Some Old Testament passages were clearly predictive, such as the place of his birth (Micah 5:2) and the crucifixion (Psalm 22). Other Old Testament passages were not as clear, such as Jesus is called out of Egypt (Matt. 2:15; Hosea 11:1). Whether obvious or hidden, Jesus was the fulfillment of all the messianic predictions of the Old Testament. The sacrificial system of the Old Testament taught God’s people that something innocent must die in their place to postpone the penalty of their sins. Jesus’ death, as the perfect and perfectly innocent sacrifice, fulfilled those righteous requirements of the law.
Additionally, Jesus perfectly kept all the commands of the law. He was “born under the law” (Gal. 4:4) “to fulfill all righteousness” (Matt. 3:5). He kept the entirety of the law and never fell short even on the smallest point. Another way he fulfills the law and the prophets is by means of the Holy Spirit operating in the citizens of his Kingdom. Paul makes this point in Romans 8:1-4 (a portion of which we already read):
There is therefore now no condemnation for those who are in Christ Jesus. 2 For the law of the Spirit of life has set you free in Christ Jesus from the law of sin and death. …he condemned sin in the flesh, 4 in order that the righteous requirement of the law might be fulfilled in us, who walk not according to the flesh but according to the Spirit. 
Believers are able to fulfill the righteousness of the law by the power of the Holy Spirit – not perfectly in this life, but perfectly in the fully-consummated Kingdom. This is the fulfillment of Ezekiel’s prophecy:
And I will give them one heart, and a new spirit I will put within them. I will remove the heart of stone from their flesh and give them a heart of flesh, 20 that they may walk in my statutes and keep my rules and obey them. And they shall be my people, and I will be their God. 
Another way Jesus fulfilled Old Testament scripture was by bringing its doctrines to light through his teaching and his person. The Old Testament is the good news in the form of un-ripened fruit. The New Testament is the gospel in full flavor because Christ is the multi-faceted and powerful fulfillment of the law and the prophets. He completely superseded and completely fulfilled it. And he authored every letter and every stroke of the law that he fulfilled. Nothing compares with his superb and mysterious authority.
So, Messiah Jesus proclaims:
18 For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished.
The smallest letter is the Hebrew yod, which looks kind of like an apostrophe. There are approximately 66,420 yods in the Hebrew text of the Old Testament. The “least stroke” is the Hebrew serif, a tiny extension on some letters made to distinguish them from similar letters. As far as I’m aware, no one has bothered to count the vast number of serifs in the Old Testament – at least no one of whom I am currently aware has admitted to completing such an obsessive task.
Jesus is not only saying that the Old Testament contains the truth or that it somehow becomes the truth in our personal subjective experience. He is saying that “the scripture cannot be broken” (John 10:35). Holy scripture and it’s teaching will not change. When Jesus quotes the Old Testament, he does so using the perfect tense – It is written – meaning It was written, it is written, and it always will be written. The scriptures are more enduring than the universe in which we live. Jesus promised, “Heaven and earth will pass away, but my words will never pass away” (Matthew 24:35).
If you had been able to be an observer in the Garden of Eden before Adam and Eve went to war with God, you could have observed them and learned what God was like. They were his perfect children, the epitome of his created world, perfect created reflections of the divine nature. But when they went to war with God, they marred his perfect image. No longer could you look at Adam and Eve (or any of their children) and know what God was like.
Because man no longer perfectly reflected God’s nature, when he called his people out of Egypt, he gave them a written revelation of his perfection. From that moment at Mount Sinai onward, if anyone wanted to know what God was like they could hear and read and meditate upon his law given through Moses. If anyone was in doubt about the dire state of humanity before a perfect God who demanded perfection from his creatures, they needed to look no further than the law and the prophets.
St Author of Hebrews expressed Christ’s person and work under the Old Covenant this way:
11 But when Christ appeared as a high priest of the good things that have come, then through the greater and more perfect tent (not made with hands, that is, not of this creation) 12 he entered once for all into the holy places, not by means of the blood of goats and calves but by means of his own blood, thus securing an eternal redemption. 13 For if the blood of goats and bulls, and the sprinkling of defiled persons with the ashes of a heifer, sanctify for the purification of the flesh, 14 how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our conscience from dead works to serve the living God. 15 Therefore he is the mediator of a new covenant, so that those who are called may receive the promised eternal inheritance, since a death has occurred that redeems them from the transgressions committed under the first covenant.
The radical righteousness that Messiah Jesus lived and taught is not out of line with the Old Testament. His righteousness is radical not because it’s new but because he lived it perfectly and completely! What’s more, if you are trusting into his perfectly-lived life and sacrificial blood-shedding death, his law is a promise for you. What was once a list of do this and don’t do that is now a description of who you already are in Christ and what you will be like in his fully consummated Kingdom.
For the pre-believer, the law is a prison. But for those upon whom the Holy Spirit is working, it is the declaration of total guilt to humble them and drive them to Christ. It does not humble them to their destruction, but to their salvation. God wounds so that he may heal again. He kills that he may raise the dead.
KINGDOM SUBJECTS AND THE LAW (19-20)
Verses 19 and 20 give us specific instructions on how the citizens of Christ’s Kingdom should relate to the Old Covenant:
19 Therefore whoever relaxes one of the least of these commandments and teaches others to do the same will be called least in the kingdom of heaven, but whoever does them and teaches them will be called great in the kingdom of heaven. 20 For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven.
When God declares certain people will be called “great” (megas) he means it. Whatever attempts we could make to understand that kind of greatness would certainly fall short. We become great in his Kingdom by keeping his commandments and teaching them to others as the Holy Spirit directs and empowers us (Rom. 8:1-14).
Some teachers hold that Jesus is promising great heavenly rewards to those who keep more commandments and lesser heavenly rewards to those who cannot or will not keep the law as perfectly. So, the one who is terribly pious and conscientious of rule keeping will have a great mansion in heaven. However, average Christians who struggle against the world the flesh and the devil might find themselves living in a cardboard box under a heavenly overpass.
However, as one writer observes:
While v. 19 sounds like an endorsement of the scribal concern to ensure that every detail of the law should be observed to the letter, v. 20 speaks of the “righteousness of the scribes and Pharisees” (which consisted of a scrupulous observance not only of the OT laws but also of their burgeoning elaboration of those laws) as something other than the righteousness of the kingdom of heaven, and warns that that sort of legal observance leaves one outside the kingdom of heaven altogether.
We might then paraphrase Jesus’ words here as follows: “Far from wanting to set aside the law and the prophets, it is my role to bring into being that to which they have pointed forward, to carry them on into a new era of fulfillment.” So, the authority of the law and the prophets is not abolished. They remain the authoritative word of God. But their role will no longer be the same, now that Jesus, to whom they pointed forward has come, and it will be for Jesus’ followers to discern in the light of his teaching and practice what is now the right way to apply the law in the light of his coming.
It is now the authoritative teaching of Jesus that governs our understanding and practical application of the law. Verses 21–48 will go on to show how this interpretation can no longer be merely at the level of the literal outward observance of regulations but must operate at the deeper level of discovering the underlying will of God. It may appear that certain elements of the law are for all practical purposes “abolished.” This is because of their changed role in this new age of fulfillment, in which it is Jesus who is the fulfiller, rather than the law which pointed forward to him. Jesus is the ultimate authority.
Hearing Messiah Jesus say, “unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven” would not have sounded AT ALL like “good news.” This would have been a shocking statement to the average listener in his day. The scribes and Pharisees made obedience to God’s law the great passion of their lives. They calculated that the law contained 248 commandments and 365 prohibitions, and they worked to keep them all.
How could anyone surpass that? And how could such super righteousness be made a condition to entering Jesus Kingdom? As we press on further into Jesus’ sermon, we will see that Jesus is drilling down to the deepest level of the human heart. He is dismissing mere outward performance and pointing to the sinful attitudes rotting away in the whitewashed tombs of external religion. He will sum up his instruction on the law with this command: “be perfect, therefore, as your heavenly father is perfect” (v. 48).
Jesus is not reversing his earlier teaching that we entered the Kingdom of God through grace. He is saying that our attitude to the law of God is an index of our attitude to God himself. If we take the law lightly and encourage others to do so, we show that we are strangers to the promise of the new covenant in Christ. But if we desire to love and keep even the least of the Lord’s commandments, and we encourage others to do so as well, that is a sign that we love Christ and belong to his Kingdom.
So we circle back to Ground Zero of the first beatitude: “Blessed are the poor in spirit, for theirs is the Kingdom of God (5:3). The law is our revelation of God’s holy and righteous character. It describes who Jesus is. It functions as the curbs on the road of Christian living. And it blesses us when we see how desperately we fail to keep it, reminding us how desperately we need Christ’s righteousness and the Holy Spirit’s re-creative power to renovate our lives.
Christ did what we can never do. He fulfilled the law perfectly and completely. His righteousness alone exceeded that of the scribes and Pharisees. And because he fulfilled the law, he can give us a righteousness that exceeds that of the scribes and Pharisees. He freely offers his perfectly-lived life and his sacrificial death to all who will trust into him. He came for the last, the last, the least, the little, and the dead – those who recognize their poverty of spirit and starve for his righteousness.
 Hughes, R. Kent. The Sermon on the Mount: The Message of the Kingdom (Preaching the Word). Crossway. Kindle Edition.
 Ferguson, 68.
 Hughes, op. cit.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Ro 8:3–4.
 Ferguson, 70.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Ro 8:1–4.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Eze 11:19–20.
 Hughes, op. cit.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Mt 5:18.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Heb 9:11–15.
 Hughes, op. cit.
 France, 180.
 Id., 181-183.
 Ferguson, 77.