At the end of Matthew 5:17, Jesus said He came to fulfill the Law and the Prophets. The Greek word pleeroo translated "fulfill" can mean to complete or accomplish. But it can also mean to fill to the full. Which understanding is correct?
We can answer that question easily by simply looking at the complete statement: "I did not come to destroy but to fulfill." Barnes' Commentary explains the meaning of "to destroy" as "to abrogate; to deny their Divine authority; to set men free from the obligation to obey them." That is, Christ did not set men free from their obligation to the law.
Interpreting "to fulfill" to mean Christ came to end the Law or the Prophets, when in the same breath, He said He did not come to end them doesn't make any sense! However, the meaning "fill to the full" does. This meaning of pleeroo is found is several New Testament passages. For instance, Romans 15:13 says, "Now may the God of hope fill you with all joy and peace in believing, that you may abound in hope by the power of the Holy Spirit."
Obviously, the correct way to understand "fulfill" in Matthew 5:17 is "to fill to the full." His complete statement means, "I didn't come to do away with the Law or the Prophets, but rather I came to uphold them in everything that I say and do."
The prophecy of the Messiah in Isaiah 42:21 helps explain what Christ did in fulfilling the law: "He will exalt [magnify, King James Version] the law and make it honorable." Jesus expanded our understanding of God's law by showing that we must obey the spirit of the law as well as the letter, as several of Jesus' following examples in Matthew 5 show.
Please review our Bible study aid The Ten Commandments for a clear and practical presentation of how God's law relates to the everyday life of a Christian. You'll see that the rest of the Scriptures verify this understanding of Matthew 5:17.