Leviticus is the third book of Moses. Leviticus is the book of the law. The main purpose of the book of Leviticus is to establish the rules and laws for a completely new form of government. It was a government establishing a nation in whose rule and direction came not from a king or leader, but from YHWH Himself. The people are preparing to enter Canaan, the promised land, and God is directing their steps. This book is the answer as to how they will succeed.