There is a lot of confusion over what it means to 'fulfill the law.' I would like to approach this topic in two different ways; 'fulfill' as an idiom and 'fulfill' in its most literal sense.
"To FulFill" And "To Destroy" As An Idiom
To 'fulfill the law' as a Jewish idiom means to "interpret correctly." And to 'destroy the law' means to 'incorrectly interpret.' Therefore, in this context, Yeshua stated His purpose was to 'fulfill' the Torah and He then proceeded to 'correctly interpret' the Torah in the sermon which immediately follows [in a "You have heard, but I say...." format.] At the time of Yeshua, the Torah had been interpreted incorrectly, many laws had been added to Torah, some of which actually contradicted the very Torah they sought to explain. Even Sha'ul warned, "From which some having swerved have turned aside unto vain jangling; Desiring to be teachers of the law; understanding neither what they say, nor whereof they affirm. But we know that the law is good, if a man use it lawfully." 1 Timothy 6:6-8 Yeshua uses the Torah lawfully, He correctly interprets its meaning for mankind.
"Therefore speak I to them in parables: because they seeing see not; and hearing they hear not, neither do they understand. And in them is fulfilled the prophecy of Esaias, which saith, By hearing ye shall hear, and shall not understand; and seeing ye shall see, and shall not perceive. For this people's heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes, and hear with their ears, and should understand with their heart, and should be converted, and I should heal them. But blessed are your eyes, for they see: and your ears, for they hear. For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them; and to hear those things which ye hear, and have not heard them" Matthew 13:13-17
Yeshua came to bring light to God's remnant -- to speak God's own Words to those who would hear and understand God's truths:
"Yeshua answered and said unto them, 'Ye do err, not knowing the scriptures, nor the power of God. For in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven. But as touching the resurrection of the dead, have ye not read that which was spoken unto you by God, saying, I am the God of Abraham, and the God of Isaac, and the God of Jacob? God is not the God of the dead, but of the living.' And when the multitude heard this, they were astonished at his doctrine. Matthew 22:29-33
Here Yeshua is correctly interpreting the Torah and applying it to the issue of resurrection. His audience 'knew' Torah, certainly they recognized the passage Yeshua quoted, but hadn't understood the full implication of the passage. Without understanding, Scripture remains veiled, but Yeshua came to bring light to God's Word.
"And when the Pharisees saw it, they said unto his disciples, Why eateth your Master with publicans and sinners? But when Yeshua heard that, he said unto them, They that be whole need not a physician, but they that are sick. But go ye and learn what that meaneth: 'I will have mercy, and not sacrifice' for I am not come to call the righteous, but sinners to repentance." Matthew 9:11-13
Again, the people here were familiar with Scripture passage Yeshua quoted, but didn't understand what the verse was really saying. Even the disciples sometimes lacked understanding:
"Then opened he their understanding, that they might understand the scriptures, And said unto them, 'Thus it is written, and thus it behoved Messiah to suffer, and to rise from the dead the third day: And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.'" Luke 24:45-47
We see that one aspect of Yeshua's ministry was to correctly interpret the Torah's meaning for mankind. Yet the modern church wrongly believes that Torah is no longer relevant *because* of Yeshua. How can this be?
It's been wrongly argued by some that believers don't have to obey Torah because Yeshua 'fulfilled' it for them. There seems to be a mass of confusion over what He fulfilled! It seems the church confuses 'fulfillment' with 'obedience.' Yeshua's obedience to Torah is separate from His fulfilling Torah. The church seems to think that Yeshua's obedience replaces our own obedience. It's like saying because Yeshua ate kosher, we don't have to. Or that because Yeshua kept Sabbath, we don't have to. Please understand that Yeshua's fulfillment wasn't through His observance (though He did perfectly obey) but His fulfillment was in correctly interpreting and teaching Torah. Yeshua brought true understanding to those who would hear.
"To FulFill" And "To Destroy" Interpreted Literally
Now let's take a different approach and interpret the Matthew 5 passage in its most literal sense. First let's define the terminology: The word 'fulfil' used here in Greek is pleroo (Strong's 4137) meaning "fill up" "make complete" "fully preach" "to supply" and "to perfect." 'Destroy' here comes from the Greek kataluo (Strongs 2647) and means "to utterly destroy" or "overthrow completely." With these literal definitions, let's paraphrase Matthew 5:17,18 "Think not that I am come to utterly destroy or overthrow the law or the prophets: I am not come to utterly destroy or completely overthrow, but to make complete and fully preach the law. For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in NO wise pass from the law, till I have finished preaching and making complete." Note that these comments apply not only to Torah but also to the Prophets! Which brings up an interesting point. When the church says Yeshua fulfilled a prophetic passage, they mean He accomplished what the passage said; but when the church says Yeshua fulfilled a Torah passage, it's as if 'fulfill' suddenly changes to mean Yeshua made the passage irrelevent by destroying or abolishing. That can't be right.
So, let's look at a few cases of literal 'fulfillments' in the Prophets:
Micah 5:1 (2) "But thou, Beth-lehem Ephrathah, which art little to be among the thousands of Judah, out of thee shall one come forth unto Me that is to be ruler in Israel; whose goings forth are from of old, from ancient days."
Matthew 2:4,5 "And when he had gathered all the chief priests and scribes of the people together, he demanded of them where Messiah should be born. And they said unto him, In Bethlehem of Judaea: for thus it is written by the prophet."
Yeshua was born in Bethlehem, thus fulfilling this prophecy. Now, fulfilling this prophecy didn't mean Bethlehem was destroyed or abolished following Yeshua's birth! Yes, I know that seems a ridiculous fact to point out. But it shows the problem within the church in fairly applying 'fulfill' across the board. When the church applies 'fulfill' to the Prophets, they use it in its literal, normal sense. But somehow, when the church applies "fulfill" to Torah, suddenly it means "destroy," "abolish" or overthrow.
Here's another 'fulfillment' from the Prophets:
Isaiah 53:4-5 "Surely he hath borne our griefs, and carried our sorrows: yet we did esteem him stricken, smitten of God, and afflicted. But he was wounded for our transgressions, he was bruised for our iniquities: the chastisement of our peace was upon him; and with his stripes we are healed."
Matthew 8:17 "That it might be fulfilled which was spoken by Esaias the prophet, saying, Himself took our infirmities, and bare our sicknesses."
And again, the church doesn't dispute that Yeshua "fulfilled" this prophecy by being the prophecied Suffering Servant. Yeshua literally fulfilled the prophecy by doing exactly as the prophecy predicted Messiah would. The church would readily agree that the Isaiah 53 passage isn't abolished or destroyed just because Yeshua fulfilled it.
With the Prophets, the church doesn't stumble over what it means to 'fulfill' a prophecy. Yet, when 'fulfil' is applied to Torah -- every effort is made by the church to reinterpret 'fulfill' as if it really meant to 'abolish'/'destroy (or even 'replace').
Let's look at a literal example of Yeshua fulfilling Torah:
Deuteronomy 18:18-19 "I will raise them up a prophet from among their brethren, like unto thee; and I will put My words in his mouth, and he shall speak unto them all that I shall command him. And it shall come to pass, that whosoever will not hearken unto My words which he shall speak in My name, I will require it of him."
John 12:49 "For I have not spoken of myself; but the Father which sent me, he gave me a commandment, what I should say, and what I should speak."
John 14:10 "Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works."
Now this is a more accurate example of how Yeshua fulfilled Torah -- by speaking God's own Word to mankind. If we correctly use 'fulfill' either literally or as the common idiom of Yeshua's day, we will not run into the error of believing Torah has been abolished or destroyed by Yeshua.
Problems With Considering Torah Abolished
"For where no law is, there is no transgression." Romans 4:15
If Torah is abolished, then there is no law, and therefore, no sin. If there is no sin, I don't need a Saviour.
"And he shall go out unto the altar that is before the LORD, and make atonement for it; and shall take of the blood of the bullock, and of the blood of the goat, and put it upon the horns of the altar round about." Leviticus 16:18
The command for blood sacrifice is contained within Torah. If Torah is abolished, then no sin offering is required of us and Yeshua would have died in vain. It is only because Torah *is* still relevant and in effect that Yeshua's atonement is so precious.
'Til All Be Fulfilled'
Matthew 5:17,18 "Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil. For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in NO wise pass from the law, till all be fulfilled.
Heaven and earth will pass away before Torah will. Not one jot or tittle will be altered "until all be fulfilled." Has all been fulfilled? Has Yeshua returned? Has *all* Israel been regathered back into the land of Israel? Has the Messianic Kingdom been established here on earth? Has the resurrection occurred? Not one stroke in Torah will be changed in any way until *all* is fulfilled