When we compare the Old and New Covenants we are also comparing two different versions of God’s law. The law of the Old Covenant is the Mosaic law and the Ten Commandments (Exodus 34:27-28, Nehemiah 8:1). The law of the New Covenant is the law of Christ (1 Corinthians 9:19-21). Even though both versions of the law of God are different from each other they both do the same things. For both the believer and the unbeliever law shows us our sin (1 John 3:4). For the unbeliever the law is condemning (Romans 6:23, Deuteronomy 28:15-45). For the believer the law tells him how he is to show his love for God (1 John 5:3). In the Old Covenant era God was emphasizing law as it relates to unbelievers, since Israel was a temporary, unbelieving picture of the people of God (Romans 9:30-10:4, Hebrews 8:7-13). In the New Covenant era God was emphasizing law as it relates to believers (1 John 2:3-6). But, in both the Old and New Covenant eras law functioned identically. In the Old Covenant era David tells us that for him, a believer, his keeping of the Mosaic law was out of love for his God (Psalm 119:97ˆ). In the New Covenant era the law of Christ was condemning for those who were not believers (Romans 6:23).
So… in both eras law does the same thing. The only difference is that our God is primarily focusing on unbelievers in the Old Covenant era and believers in the New Covenant era. It could be said that each Covenant era has a different flavor of law.