God established a priesthood out of the tribe of Levi (one of the twelve tribes of Israel) in order to mediate the Law and forgiveness of God to the people of God. The priests served as a constant reminder of the gravity of sin, the need for redemption, and the power of declared forgiveness. The priests mediated the daily sacrifices and extended the word of forgiveness to the people.
Once a year the people of God would set apart a special day known as the Day of Atonement (Yom Kippur). This was the holiest day of the year. No one would work on that day and everyone would fast and confess their sins before God. The high priest would enter the holy of holies and offer a special sacrifice for the sins of the people, including the sins of the priests. The blood of a bull would be sprinkled on the altar as a sign of the payment for sins. One of the most notable features of the Day of Atonement was when the priest took two goats and brought them into the presence of God. One of the goats would be sacrificed for the sins of the people. The priest would then lay his hands on the second goat and confess the sins of Israel over the goat and then take the goat out into the wilderness and release it. It was symbolic of their sins being atoned for and carried far away from the people of God.