The Day of Atonement - the day where God's people and God's place are declared clean and forgiven, what do the people do to contribute? Nothing, they bow the knee to the One who provides the way.
Leviticus 8 presents to us the ordination of the priests. We see in the ordination of the priests the wonder of the work of Christ in the hearts and lives of sinners like you and me.
Here, in this new section, the Lord addresses what's to be done with unintentional sin. As much as we are reminded of the sinfulness of sin in this passage, we ought to be reminded of the grace of God - He has provided a way to deal with that sin!