Why did God give the people of Israel the law which could not be observed? What is the real purpose of the law?

Men do not observe the law without the Holy Spirit because men thmselves ae not good. Was there Holy Spirit in individuals in the Old Testament times like New Testament times? No, the Holy Spirit had gone after Adam and Eve's sin. After that, God tried tobring back the Holy Spirit to men. What is the Holy Spirit? It is Love itself, Truth itself, Peace itself, and Freedom itself which can lead to the perfect law. God knew that men in the Old Testament could not obey the law. Why did God give the people of Israel the law which could not be observed? God was waiting for them until they lay down their goodness, their righteousness and their will. God used the people of Israel as an example in order to teach love to both the gentiles like us and the people of Israel through a very long history. God wanted to let us know that the men cannot follow the law without love. With a sense of judgment, the more the men try to follow the law, the more they have anxiety and condemnation. Worse, in order to be perfect like a god, men must keep the law. What is the genuine purpose of the law? God is not only for the living on this earth happily but also for living and reigning with Jesus for a thousand years and forever as a priest.