So the law was put in charge to lead us to Christ that we might be justified by faith.
Paul continues to marshal arguments against the teaching threatening the new churches he established in Galatia. Against the false teachers who were attempting to bind certain requirements of the Law of Moses upon students of Jesus!
He advances two arguments against keeping the Law of Moses:
1. The promise of salvation by faith in Jesus pre-dates the Law of Moses - The law, introduced 430 years later, does not set aside the covenant previously established by God and thus do away with the promise.
2. If salvation depends on keeping the law, then the promise shared with Abraham would be unnecessary - For if the inheritance depends on the law, then it no longer depends on a promise; but God in his grace gave it to Abraham through a promise.
Paul then proceeds to answer the question – Why then was the Law of Moses given?
It was added because of transgressions until the Seed to whom the promise referred had come…Now that faith has come, we are no longer under the supervision of the law.
The Law cannot save from sin, because nobody can keep the Law perfectly. That’s why salvation must come through the grace of God. A promise of God, not a covenant of Law.
The coming of Jesus is the promise made to Abraham. Salvation then is by faith in Jesus, not by keeping the Law. Those teaching the necessity of keeping parts of the Law of Moses are mistaken.
But the Scripture declares that the whole world is a prisoner of sin, so that what was promised, being given through faith in Jesus Christ, might be given to those who believe.
Students of Jesus are only and completely saved by faith in Jesus!