“But when the fullness of the time had come, God sent forth his Son, born of a woman, born under the Law, to redeem those who were under the Law, that we might receive the adoption as sons” (Gal 4:4-5). Jesus was born “under the Law.” Through the centuries, various views on the nature of the Mosaic Law have been bandied about in the church. Some have understood the Law in contrast to the Abrahamic covenant as God instituting an impossible meritorious system of salvation. If someone could keep the Law perfectly, he would be counted righteous and, therefore, earn his salvation. But God, knowing that no one could do this, sent Jesus to earn salvation with works of supererogation so that there is now an infinite treasury of merit for all who believe.
This may sound good prima facie, but it doesn’t fit the biblical evidence. For example, how could David, a man who was under the Law, plead with God to “Judge me, O Yahweh, according to my righteousness, and according to my integrity within me” in Psalm 7:8? How could Paul say without snark, “concerning the righteousness which is in the Law,” he was blameless (Phil 3:6)? How could Luke record of Zechariah and Elizabeth, the parents of John the Baptizer, “And they were both righteous before God, walking in all the commandments and ordinances of the Lord blameless” (Lk 1:6)? If no one could keep the Law, how then do we account for these (and many more) instances where the Bible says that people were righteous according to the Law?
Furthermore, how can the Law be a meritorious system of works-salvation when the Law itself provides the place and means for the forgiveness of sins? God creates a place–the Tabernacle–and the prescriptions–the offerings/sacrifices–for his people to deal with their sins and the sins of the world. If the Law is a meritorious ladder to salvation, only condemning, why does God provide forgiveness for sins? (Albeit, it is temporary forgiveness, but genuine forgiveness nonetheless.) A man keeps the Law when he offers the prescribed offerings for sin. This is difficult to squeeze into a merit-your-salvation view of the Law.
Some have pitted Moses against Abraham in a Law vs Grace/Gospel soteriological death match that is nowhere justified by Scripture. With the Law at its heart, the Mosaic covenant is the Abrahamic covenant that died and rose again. One obvious indicator of this is the continuing sign of the Abrahamic covenant: circumcision. Circumcision was instituted as a sign of the Abrahamic covenant in Genesis 17 to be given to every eight-day-old male within Abraham’s family. Circumcision was a sign of death. A male from the family of Abraham would be the seed of the woman promised in Genesis 3:15, who would be “cut off” (die) to crush the serpent’s head. Circumcision becomes so identified with the Law that Paul tells the Galatians that those who are circumcised become debtors to keep the whole Law (Gal 5:3). The sign of the Abrahamic covenant becomes inseparable from the Law. The two are not at odds. Law and grace are not enemies.
The Law is a glorification and explication of circumcision. Circumcision cut off Abraham’s seed from the rest of humanity, ripping humanity into two pieces that eventually came to be known as Jews and Gentiles. Abraham’s seed was separated from the world for the sake of the world (Gen 12:1-3). The Law, with all of its prescriptions and proscriptions that distinguished Israel from the rest of the world, designated a people and a place for the sin of the world to receive justice. The Law separated Israel for the sake of being led as a lamb to the slaughter for the sin of the world. The promise given to Abraham must go through the Law, and going through the Law means death. Death is always followed by resurrection in God’s economy, but death is unavoidable. The Law graciously provides the place and people–eventually, the person–who will die.