Heb.8:7-9 – For if that first covenant had been faultless, then no place would have been sought for a second. Because, finding fault with them, He says: “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 when I took them by the hand to lead them out of the land of Egypt; because they did not continue in My covenant, and I disregarded them, says the LORD.
Why was there a need for the Lord to establish a new covenant with the people of Israel? What was wrong with the Old Covenant? Actually there was nothing wrong with the Old Covenant, it was perfect. The problem was not with the covenant it was with fallen man. No one had the ability to fulfill the demands of the Old Covenant. Actually, that was its intended purpose, to expose our sinfulness. Paul talked about this in Romans 7:7 – “What shall we say then? Is the law sin? Certainly not! On the contrary, I would not have known sin except through the law. For I would not have known covetousness unless the law had said, “You shall not covet.”” Paul described the simple law “You shall not covet” that exposed the sinfulness of his heart. The law exposed our sins but could not change us. Here is how the Believer’s Bible Commentary describes this conflict:
“Actually, the trouble was not with the first covenant itself: “the law is holy, and the commandment holy and just and good”. The trouble was with the people to whom it was given; the law had poor raw materials to work with. This is stated here: Because finding fault with them, He says …. He did not find fault with the covenant but with His covenant people. The first covenant was based on man’s promise to obey, and therefore it was not destined to last very long. The New Covenant is a recital, from beginning to end, of what God agrees to do; this is its strength.
The writer now quotes Jeremiah 31:31–34 to show that in the Jewish Scriptures God had promised a New Covenant. The whole argument revolves around the word new. If the old was sufficient and satisfactory, why introduce a new one?”
So the law exposes our sinfulness and shows us our need for a Savior. Christ came to be the mediator of a new and better covenant. This covenant not only has the power to cleanse our sins but also the power to change our lives. In Christ all things have become new, we are literally different people than who we were before we met Him.