When Jesus spoke of the Old Testament, He spoke of "the Law and the Prophets". For example, Jesus said "Do unto others as you would have others do unto you. This is the law and the prophets". Here Jesus is saying that if you want to understand in one phrase biblical ethics it is this "do unto others as you would have them do unto you". So in Jesus day the sacred text was called the law and the prophets. The books of Moses, Genesis, Exodus, Leviticus, Deuteronomy, and Numbers, were called "the Law".
Paul explains to us what the purpose of this portion of scripture is. The purpose of the Law is to "reveal to us the sinfulness of sin". In Galatians, Paul says the purpose of the law is to shut up everyone under sin". The purpose of the Law is to convict us of sin. Then, we who were held in bondage to the elemental principles of the world were set free from the law and from sin through Jesus Christ. The law Paul is saying was not ever created for the purpose of making anyone holy or righteous. The law was not made to make a holy society like the Muslims believe. And if someone uses the Law for something it was never made to do, Paul says that this use of the Law is destructive. We are to use the Law for its limited function. The purpose of the Torah is to tell the story of the sinfulness of sin. In the life of the people of God, the practice of Law was not to make the society healthy or whole or righteous but to convict of sin. When a person was stoned for adultery, we were not to say "this is making our society holy by getting rid of evil doers". Instead, this was to convict us of our own sinfulness and guilt for have not all of us contemplated the same act but were without opportunity. Oh God...I am guilty. So this is the sole purpose of Torah, of the Law, to convict us of our sin.
This conviction being the purpose of the Law, then the purpose of the "prophets" was to present the promise, the promise of deliverance from our sin in the Messiah. When we understand the purpose of the Law, we then see the promise in the prophets. The prophets’ foundational and primary role was to encourage the sinful people of the hope of deliverance from sin. This deliverance was to come to the sinner by grace and through faith, and indeed this deliverance has come in Jesus Christ.
So this is the purpose of the Law to convict of sin. The Torah tells a story to explain to the people of God why there is such oppression and injustice in the world. Why is there this insanity of Pharaoh? Why would a king seek to be worshipped as a God? Why do we need a nation built on law and not on the authority of a despot? Because of the sinfulness of sin.
The story of the sinfulness of man starts with man's most primitive desire. The desire to be God. So the first sin, the foundational sin, was the direct attempt to be the independent sovereign ruler of one's dominion. Satan told the first man, "if you eat of the tree of the knowledge of good and evil, your eyes will be opened and you will be like God able to discern good from evil and make your own choices. You will have your own absolute personal sovereignty". You will need no Father for you will be your own father. You will have total existential authority over your own universe. This is the foundational sin that defines the spiritual DNA of natural man. Oh man, this is what you are by nature and all mankind is taken from the same pool.
From this spiritual gene pool came Cain and Able. This story was followed by the story of the violence in Noah's time and then the story of the tower of Babel. Then there is the story of Sodom and Gomorrah. Then the story of Jacob and Esau and the story of Joseph and his brothers. Then the story of Pharaoh...This is all the story of the sinfulness of mankind. The purpose of all of this is to reiterate one theme - the sinfulness of sin. Be convinced, we are all sinners.
The story has a thematic point, an overwhelming and overarching theme, to define clearly the problem of mankind's inherit sinfulness. This is the purpose of the Law. Whenever we use the Law for any other purpose, we are using the Law in ignorance. To use the Law or the Torah for any other purpose is like using a surgical tool to pound a nail. Would we use a CAT scan machine to hang drywall? Would we use a stethoscope to drive to work? No, we use a hammer to hang drywall and a car to drive to work. One of the lessons we constantly teach our children is that things are made for certain functions. Paper is not food. Don't use my guitar as a step ladder. So too, do not use the Torah as a science text or as a means to obtain righteousness. The Law is to be used as a spiritual tool to convince people of the sinfulness of man. It does this by showing man's desire to be God and man's propensity toward violence. The Torah shows the danger of anarchy due to the sinfulness of man and the need for Law and government to rule over us because we are all sinners.
God Bless, brad