“Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil. For truly I tell you, until heaven and earth disappear, not the smallest letter, not the least stroke of a pen, will by any means disappear from the Law, till all be fulfilled.”
Matthew 5:17-18 KJV (Italics from NIV)
It is important to realize that Jesus didn’t come to destroy or abolish the Law or the Prophets (speaking of the Old Testament), rather He came to fulfil them. The word “fulfil” means to make full, to perfect, complete or finish. Jesus is saying that He came to complete the law, or to bring it to an end. He came to perfect it. We’ll all agree that Jesus did what He came to do, and therefore the law is now complete or brought to an end. Matthew 5:18 shows us that the law stood until all was fulfilled. In John 19:30, Jesus was hanging on the cross and He declared in His final breath that “it is finished”. Jesus had come to fulfil the law and through His sacrifice, He did it. He completed it and brought it to an end, so that we could relate to God under a new and better covenant.
“Why then the law? It was added because of transgressions (sin; violation)…
So then, the law was our guardian until Christ came, in order that we might be justified by faith. But now that faith has come, we are no longer under a guardian, for in Christ Jesus you are all sons of God, through faith.”
Galatians 3:19; 24-26 ESV (Brackets mine)
The word “added” shows us that law was not a part of God’s original plan. The law (the covenant which came through Moses) was “added” to the Covenant of Promise that God had already made with Abraham. The purpose of this was to expose sin and show that self-salvation could never be attained. The law prepared us for the covenant of grace (through Jesus) in which we need to let go of our effort for acceptance and blessing, and trust in our Saviour.
“So then, the law was our guardian until Christ came”
Galatians 3:24 ESV
The word “until” shows us that the law was a temporary situation “until Christ came”. Jesus came to fulfil the law; complete it and bring it to an end.
“For Christ is the end of the law for righteousness to every one that believeth.”
Romans 10:4 KJV
It is not possible to obtain right standing (righteousness) before God based on our effort and obedience to the law. It’s only by faith (believing) in what Christ has done for us.
“I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.”
Galatians 2:21 KJV
If you could be right with God by obeying and living by the law (the Old Covenant), then it would frustrate (void, stop the flow or reject) the grace of God (the free gift of undeserved favour) and it would mean that Christ’s death had no purpose.