Leviticus is about holiness. The first part of the book is about worshiping our holy God and the second part is about living a holy life pleasing to Him. Leviticus 1 is about offering burnt offerings of animals sacrificed from the herds and flocks of the Israelites. Many details were given as guidance in how to do this properly and exactly in order for the Lord to accept the sacrifices as their substitute, making atonement for the Israelites. Whether a bull, male sheep, turtledove, or young pigeon, they were to be offered as a "whole burnt offering made by fire, very pleasing to the Lord". The animal sacrifices were offered from their own flocks and herds and only animals with no physical defects were to be chosen. Only the holy priests were to perform the sacrifices, sprinkling the blood, and placing the animal on the fire. The offering process demonstrated God's justice, holiness, and mercy; and it also demonstrated the Israelites' dependence, commitment, and submission to God's laws.