The Law’s purpose was temporary. Unlike God’s unchanging covenant with Abraham, the Mosaic one was at risk due to Israel’s persistent rebellion (Dan. 9:7-14; Hos. 6:7; 8:1). The solution God promises is not a renewal of what He gave at Sinai, but a new arrangement “not like the covenant I made with their fathers on the day I took them by the hand to bring them out of the land of Egypt, my covenant which they broke” (Jer. 31:34). That promise of something new was not lost on its intended audience.
The end of the Old Covenant came as He promised. God dramatized it marvelously with one great climatic event, which occurred when Jesus died on the cross. The veil of the Temple was torn from the top to the bottom, signifying that God had ended the whole system. The Holy of Holies was exposed. Access to God was open to all. The shadows gave way to the substance. And just to make sure no one was confused about the old system, in A.D. 70 God allowed Jerusalem and the Temple to be destroyed. It has never been rebuilt.
By the new covenant, the Spirit gives life and righteousness (Rom. 8:2). The old covenant commands righteousness; the new covenant confers it. The old covenant made people hearers of the truth; the new covenant enables them to be doers of the truth.
[Without the Spirit] the old covenant prescribed what men were to do but could not enable them to do it. It provided a basis for damnation, but not salvation; for condemnation, but not justification; for moral culpability, but not for moral purity.
All that the old covenant was ever intended to do was to drive men to despair and then the despair to plead for mercy and grace from a kind and loving God… When an Old Testament person saw the Law for what it really was, a ministry of condemnation, a ministry of death, and when they were slain, as it were, and when they feared hell, and when they realized their sinfulness, and when the Law had done its work and they had a repentant heart and they came to God and pleaded for mercy and pleaded for grace and pleaded for forgiveness which they didn’t deserve but which they pled for, and God in grace looked at them and forgave them, that work of transformation that occurred there was the Spirit of God’s work. And He was applying the new covenant work of Christ retroactively to that penitent sinner. But it was the Spirit’s work. Salvation any time whether in the Old Testament or the New Testament under the old covenant or the new covenant was, is, always will be the work of the Spirit who is none other than the Lord. And isn’t it marvelous, the same God who wrote the Law is the same God who liberates the repentant sinner from the bondage of the Law?
When the law was written on tablets of stone, there was a significant weakness. The weakness of the Old Covenant was not in the law. The weakness of the Old Covenant was the people’s hearts. They couldn’t keep the law because they lacked two basic ingredients. Both of them interestingly were mentioned in the Old Testament when God used His prophets to speak while under the Old Covenant of the coming New Covenant. First, as God said through Jeremiah, “I will put My law within them and on their heart I will write it” (Jer. 31:34). The writing of the law went from tablets of stone to tablets of human hearts (2 Cor. 3:3). And second, as God said through Ezekiel, “I will put My Spirit within you and cause you to walk in My statutes, and you will be careful to observe My ordinances” (Eze. 36:27). We by far have greater power to obey the law with the fullness of the Holy Spirit dwelling within us as God says, “causing” us to obey. So there should be a radical difference between us and Israel. It’s not in the God we serve. It’s not in the desire to obey Him. It’s not in the faith of a Messiah to take away our sins. It’s not in a law that is given from God to be obeyed. It’s not even in a delight in that law. The difference is simply this. The Old Covenant is characterized by people who were stiff-necked and rebellious (Dt. 9:6; 10:16; 31:27), whereas the New Covenant is characterized by people who have soft hearts and the ability to obey.