The Law of God

The Law was given to Israel and the call of God was to be holy as I am Holy. This call to be holy meant that they had to live a life that was separated unto God and was well within their ability to keep. The requirements for that holiness was made very clear to them Their refusal to obey the Ten Commandments was unacceptable to God even though we later understand that the Law was like a mirror to reveal the sinful nature in man. However the Law was a very legitimate demand from God and He worked in every way so that they would begin to obey. Their disobedience revealed their wickedness and not their helplessness. They were not trying desperately hard and still not succeeding. They were just not willing to obey.
Jesus in the New Testament brought the Law to an impossible level of obedience but it was never so with the Law of Moses. We have to distinguish between the legitimate demand of God in the Old Testament and the impossible demand of Jesus in the Sermon on the Mount. The age of the Law showed man's failure to obey God. Jesus came to reveal to man that he needed God to obey God.