As can be seen in Galatians 3:17, the law came 430 years after the Abrahamic Covenant. It had a definite starting point: at Mount Sinai where the law was given to Moses by God (Exodus 19-31). But it also had an ending point: the arrival of Christ, the Gospel He handed down to the multitudes from another mountain (Matthew 5-7), and His death and resurrection. Galatians 3:19 and 25 points this out, and Jesus Himself indicates this in Matthew 5.

The meaning of this Scriptural passage depends on how one defines the meaning of the two key words law and fulfill. Does the law refer to the Ten Commandments, or does the law refer to the whole Old Covenant? Does fulfill mean "do, and keep on doing" or does it mean "do" in the sense that when it is once done, it is accomplished and no longer needs to be done again? There are traditionally two ways this text is interpreted by Christians. (8)

The first is that Jesus unmistakably teaches that the Ten Commandments are to continue and will not come to an end. This means that Christians must live in accordance with the Ten Commandments, which includes Sabbath observance, for not even the smallest letter or part of a letter is to be removed from this law. Those who teach that the law is abolished are clearly going against the will of Christ. The second is that Jesus clearly teaches that the whole law (including all that is written in the Torah) is to remain in force "until all is accomplished." By His life, death, and resurrection Jesus fulfilled or accomplished all the Old Covenant law (including the prophets). So this law is no longer binding on Christians. (9)

This is made more apparent since the Greek word translated as "fulfill" in this passage is pleróo, which means to finish a task, to complete in regards to bringing about a prediction or prophecy, or to accomplish. And in the book of Matthew, every time the word "fulfill" is used, it is used in connection with the life of Christ or the events connected with it. In every case it was one event which fulfilled a prophecy. In every instance Christians are not required to participate in any kind of ongoing fulfillment. The following list of passages in Matthew illustrate this point. Below are listed all the other passages of Matthew that contain the word translated from the Greek text to mean "fulfill" or "fulfilled":

When we look at the context of Matthew 5:17-19 we immediately see that Jesus uses law with the prophets. The context here seems to indicate the law to be the Torah. So it seems reasonable to conclude that the law Jesus referred to was the entire Old Covenant law, which included the Ten Commandments. These passages in the Gospels of Luke and John indicate this as well.

Luke 16:16
"The Law and the Prophets were proclaimed until John [the Baptist]; since then the gospel of the kingdom of God is preached, and everyone is forcing his way into it."

These words of Christ speak of a new age being inaugurated. The end of the period of the Mosaic Law and the Prophets, and the beginning of the age of the Gospel and the Christian Church, where both Jew and Gentile alike could take part.

For these reasons it is logical to interpret the word "fulfill" in Matthew 5:17-19 as referring to something that Jesus would do in connection with His work as the Messiah. Christians should not read into this passage any ongoing fulfillment in which they participate. With this in mind, this passage in John 19 makes understanding Matthew 5:17-19 easier.

This Scriptural passage is crucial to a correct understanding of Matthew 5:17-19. Here we see that Jesus had already accomplished all but one of the prophecies regarding the life and death of the Messiah, so Jesus said, "I thirst", thereby fulfilling the prophecy of Psalm 69:21. When we let Scripture interpret itself, the meaning of this passage in Matthew becomes clear. It comes just before the six times He says, "You have heard ... but I say to you." In this context it is evident that Jesus is taking authority to Himself greater than that of the Old Covenant law. His listeners would have found it easy to come to the conclusion that He was completely doing away with the binding nature of the Old Covenant. This Jesus would do, but not before He completely fulfilled the prophecies, types and shadows which pointed forward to His work as the Messiah and Savior of the world which are recorded in the law. Therefore, the law must continue until He has accomplished everything. This happened, according to the passage from the Gospel of John above, at the death of Jesus.

This interpretation seems to be the only one supported by the contextual setting. If one were to conclude that Jesus was teaching the ongoing nature of the law in this passage, the Christian would immediately be faced with a predicament. For this Scripture expressly states that "not the smallest letter or stroke shall pass away from the Law." Thus, if the Christian is going to use this text to prove the perpetuity of the Ten Commandments which were part of the Old Covenant law, then that person must also use it to prove the binding nature of all the Old Covenant law. One cannot take a subset of the Old Covenant law and declare it binding while ignoring the rest of it. One cannot insist that the sign of the Old Covenant, the Sabbath, must be kept while disregarding the rest of the Mosaic Law. The same would go for abstaining from certain foods as outlined in Old Covenant law and commanding others to do so. In writing to the Christian Church in Galatia, Paul warned his readers that they could not take only part of the law and leave the rest.

Galatians 5:3
"And I testify again to every man who receives circumcision, that he is under obligation to keep the whole Law."

We are left with two choices: Jesus fulfilled the law for us and thus freed us from the dominion of the Old Covenant, or we must keep every part of the Old Covenant. These appear to be the only choices.