“And this I say, that the law, which was four hundred and thirty years later, cannot annul the covenant that was confirmed before by God in Christ, that it should make the promise of no effect. For if the inheritance is of the law, it is no longer of promise; but God gave it to Abraham by promise” (Galatians 3:17-18).
For the Jewish people of first-century Israel, the act of becoming a Christian meant more than simply accepting Jesus as the Messiah. It meant giving up their attempts to find acceptance with God by keeping the Old Testament Law. It meant accepting Jesus’ substitutionary death on the cross as the sole basis of their justification. It also meant leaving centuries of cultural and spiritual tradition behind to find salvation by grace through faith in Christ alone.
Its difficult to understate the revolutionary nature of that first-century gospel message, and this helps explain why Paul the Apostle has spent so much time discussing the relationship between the Old Covenant and the New Covenant here in Galatians chapter three. One key point in Paul’s argument was the Law did not annul God’s righteousness-by-faith covenant with Abraham: “The law, which came 430 years later, does not revoke a covenant that was previously ratified by God and cancel the promise” (HCSB).
You see, any attempt to find acceptance with God through the works of the Law meant that Jesus’ sacrificial death was insufficient. It also meant that Jesus made a mistake when He said on the cross, “It is finished” (John 19:30). In the words of one commentator, “Works added to faith would annul the entire covenant since any dependence upon works means that it is necessary to abandon faith. That means that any sinner who claims to be saved on the basis of works plus faith is still a lost sinner.”
This same commentator also went on to make an important point…
“The Judaizers not only attempted to retain the Mosaic institutions for the Jews, but tried to impose them upon the Gentiles, to whom that law was never given. This was what Paul was fighting. Paul’s argument therefore is as follows. If a covenant once in force cannot be changed or rendered void by any subsequent action, God’s covenant with Abraham cannot be changed or rendered void by the subsequent law. If this principle holds good in a human covenant, much more is it true when God makes the covenant, since God is more certainly true to His promise than man.” (1)
(1) Kenneth S. Wuest, Word Studies in the Greek New Testament (3:17) Copyright © 1942-55 by Wm. B. Eerdmans Publishing Co.