The presence of God on Sinai was unlike any other message ever preached. We cannot stand before the judgment of God alone. We must have Christ as our mediator. We cannot stand on our good works, our good deeds or anything else. God speaks to man in many ways and the law had been placed in their heart. Their hearts had been filled with sin and had suffocated the law. God had to remind them of the original law with the Ten Commandments.
The law is given and no man can live up to it or even measure it. It reveals our true nature and the need for redemption. Then we see judicial law given. This has been carried down through time as a basis for the law of the land.