The Law or First Covenant was interimly given as a consequence, it was subject to be replaced.

One must also understand, that once JESUS Christ had come, He is the promised seed was also authorized to establish a new, better & final covenant, thereby replacing that old covenant called the Law, which though Holy, Just & Good (Romans 7:7,12) was incapable of producing in the believer that perfection, which Christ required & demanded.