The Christian Bible is divided up into two major sections. If you have a full sized Bible, you’ll find right before the book of Genesis a page that says “The Old Testament.” Then right after the book of Malachi and before the book of Matthew you’ll find a page that says “The New Testament.” I want you to do something for me. I want to you rip out the page that says “The New Testament” because it’s in the wrong spot of your Bible. It doesn’t belong there and it’s causing great confusion to many Christians.
Now, I’m (mostly) joking about ripping pages out of your Bible, but I want to make a clear point about when the Old Testament (or Old Covenant) ended and when the New Testament (or New Covenant) started. If you get this wrong you’ll be all kinds of confused when reading through the Bible, especially the Gospels.
The Old Covenant
The Old Covenant was an agreement that God made with the people of Israel through Moses on Mount Sinai. It was a covenant of works that promised blessing to the Jews if they kept the laws of the covenant.
Now therefore, if you will indeed obey My voice and keep My covenant, then you shall be a special treasure to Me above all people; for all the earth is Mine. And you shall be to Me a kingdom of priests and a holy nation.
That covenant went into effect when Moses came down that terrible mountain with tablets of stone and it continued on for hundreds of years.
The New Covenant
Eventually, the prophet Jeremiah prophesied about a New Covenant God would establish with the divided nations of Israel and Judah. It would be different from the Old Covenant established during the Exodus from Egypt.
"Behold, the days are coming, says the LORD, when I will make a new covenant with the house of Israel and with the house of Judah— not according to the covenant that I made with their fathers in the day that I took them by the hand to lead them out of the land of Egypt, My covenant which they broke, though I was a husband to them, says the LORD.
The Old Covenant would eventually end, but not until the advent of the New Covenant that was meant to replace it. The Bible tells us exactly when the New Covenant was established.
For this is My blood of the new covenant, which is shed for many for the remission of sins. Matthew 26:28
During the last supper, Jesus told His 12 disciples that this new covenant would be established in His blood. What that means is that the Old Covenant, the Law of Moses remained in effect throughout the entire earthly ministry of Jesus.
Jesus taught the Old Covenant, not the New
Many Christians believe (usually unwittingly) that Jesus taught under the New Covenant. It makes sense right? The gospel accounts are found in the New Testament, so He must have been teaching the New Covenant. But let’s look a bit more closely at what Jesus Himself actually says about that.
"Do not think that I came to destroy the Law or the Prophets. I did not come to destroy but to fulfill. For assuredly, I say to you, till heaven and earth pass away, one jot or one tittle will by no means pass from the law till all is fulfilled. Whoever therefore breaks one of the least of these commandments, and teaches men so, shall be called least in the kingdom of heaven; but whoever does and teaches them, he shall be called great in the kingdom of heaven. Matthew 5:17–19
Jesus did not destroy or in any way undermine the Law of Moses or the Prophets. In fact, He says that He came to fulfill the Law, to keep it in full. He warned them to keep even the least of the commandments of Moses.
During His ministry on earth, Jesus only ever upheld the Law as an obligation for every Jew. He rebuked leaders who would keep the minor parts of the law like paying tithes on their small herb gardens, yet neglecting the weighty matters of the law like justice.
"Woe to you, scribes and Pharisees, hypocrites! For you pay tithe of mint and anise and cummin, and have neglected the weightier matters of the law: justice and mercy and faith. These you ought to have done, without leaving the others undone. Matthew 23:23
When you understand that Jesus taught His audience to keep the Old Covenant, that changes everything. When we read about the things that Jesus did and the things He taught, we can have a better perspective on where He was coming from.
As New Testament Christians, we rightly read the Old Testament in light of the New, understanding that the commandments given to the Jews are not always directly applicable to us as blood-bought believers. Yet, we should be careful to do that same thing when we read the Gospels, since they are not the beginning of the New Testament, but are the conclusion of the Old Testament.
For they [Jews continuing to follow the Law of Moses] being ignorant of God's righteousness, and seeking to establish their own righteousness, have not submitted to the righteousness of God. For Christ is the end of the law for righteousness to everyone who believes. Romans 10:3-4