Jesus said that he didn't come to destroy the law but to fulfill it. What does it mean to fulfill the law? The word "fulfill" is from the Greek word pleroo, which has a wide range of meanings:"satisfy, execute (an office), finish (a period or task), verify (or coincide with a prediction (be) complete, end, expire, fill (up), fulfill, (be, make) full (come), fully preach, perfect, supply."
There are several ways in which Jesus Christ fulfilled the Old Testament. Christ fulfilled the Law by obeying it perfectly, by carrying out every one of the righteous demands of the Law. On one occasion He asked, "Which one of you convicts Me of sin?" (John 8:46), to which no one responded affirmatively. He was the sinless Lamb of God and was without spot or blemish. Therefore, He fulfilled the Law by perfectly meeting its righteous demands.
Christ also fulfilled the Law by fulfilling all the types and prophecies of the Old Testament. All of the illustrations in the Old Testament sacrificial system focus on and find their fulfillment in Him. All of the prophecies given regarding the coming Messiah, His kingdom, and His salvation find their fulfillment in Him.
The ultimate way that Christ fulfilled the Old Testament Scriptures, the one which gets the greatest emphasis in the New Testament, is that He met the righteous demands of the Law in providing salvation through His death on the cross. Thus He has fulfilled the Law and brought it to completion by paying the penalty for our sins.
Again, if we look at Matthew's use of this word "fulfill" it will help us understand exactly what he means:
Matthew 1:21-23 (NKJV) "And she will bring forth a Son, and you shall call His name JESUS, for He will save His people from their sins." 22 So all this was done that it might be fulfilled [pleroo] which was spoken by the Lord through the prophet, saying: 23 "Behold, the virgin shall be with child, and bear a Son, and they shall call His name Immanuel," which is translated, "God with us."
Matthew 2:15 (NKJV) and was there until the death of Herod, that it might be fulfilled [pleroo] which was spoken by the Lord through the prophet, saying, "Out of Egypt I called My Son."
Matthew 2:17 (NKJV) Then was fulfilled [pleroo] what was spoken by Jeremiah the prophet, saying:
Matthew 2:23 (NKJV) And he came and dwelt in a city called Nazareth, that it might be fulfilled [pleroo] which was spoken by the prophets, "He shall be called a Nazarene."
Matthew 26:56 (NKJV) "But all this was done that the Scriptures of the prophets might be fulfilled [pleroo]." Then all the disciples forsook Him and fled.
Seventeen times Matthew uses the word pleroo and in fifteen of them it clearly refers to prophecy being fulfilled or coming to pass. The law, which we read in the Old Testament and everything that has been said by the prophets, was going to be fulfilled by Jesus down to the minutest detail. And until it was all fulfilled, it was binding on the people of God.
The law has been fulfilled:
Hebrews 7:18 (NKJV) For on the one hand there is an annulling of the former commandment because of its weakness and unprofitableness,
This is truly an amazing statement. God is promising to set aside the Mosaic Law and the Levitical system. The word "annulling" is from the Greek verb athetesis. It is a legal term that points to the complete cancellation of the commandment in question - the Mosaic law. The same verb is used in 9:26 translated: "putting away".
Hebrews 9:26 (NKJV) He then would have had to suffer often since the foundation of the world; but now, once at the end of the ages, He has appeared to put away [athetesis] sin by the sacrifice of Himself.
The disappearance of the Mosaic law is as absolute as the putting away of sin.
The purpose of the Law is stated in Galatians 3 where it is indicated that the Law is to reveal our sinfulness and to serve as a tutor or schoolmaster to bring us to Christ. Paul says in Galatians 3 that now that Christ has come, we are no longer under the schoolmaster. Now that Christ has come and the Law has been brought to its completion, the Law has been fulfilled in Christ:
Galatians 3:24-26 (NKJV) Therefore the law was our tutor to bring us to Christ, that we might be justified by faith. 25 But after faith has come, we are no longer under a tutor. 26 For you are all sons of God through faith in Christ Jesus.
Has the Law, the Old Covenant, been fulfilled in Christ? I don't know of any Christians who would say that every single Old Testament ceremonial law is still currently in force. Yet Jesus said that heaven and earth absolutely had to pass away before the slightest letter of the Law could be fulfilled. Thus, if the Law has been fulfilled, the heaven and earth Jesus spoke of must be already taken out of the way.
We can tell that Jesus obviously was NOT speaking of the literal earth He was standing on and the literal heavens He was standing under. If we understand heaven and earth in that passage to be physical, then the Law is still in effect, and we are all in big trouble. If we understand heaven and earth as figurative, then it is possible that they have passed along with the Law.
Believer, I want you to understand that the law was a whole, and it was all in effect until it all passed away. Does this mean that we are free to do whatever we want? No, as believers we are not under the Old Covenant Law, but we are under the Law of Christ:
More at this link:
The Law is Fulfilled, Matthew 5:17-18