Why was Israel under the Law for 1500 years?
Israel was under the Law for 1500 years as a schoolmaster to bring the nation to the place where it could be justified by faith, not by law keeping, and to bring it to believe who Jesus was—the promised Redeemer, King, and Messiah foretold throughout the Old Testament.
Les explains that from Exodus chapter 20 onward, Israel was under the Law, and it was law and faith together that brought an individual Jew into a right relationship with God—not faith plus nothing as taught later. The Law served as a schoolmaster to bring Israel to the place of justification by faith. It remained until the Law was totally satisfied at the cross, where Christ died and satisfied its demands. Its purpose was to bring Israel to the place where they could have believed who Jesus was, because all through the Old Testament the prophecies looked forward to the coming of their Redeemer, King, and Messiah. Israel should have known and could have known who He was from the Old Testament, but they were steeped in unbelief.