The sin offering (Lev 9:15) highlights the confession of sin and absolution. Without an initial confession of sin, we are worshipping God with unclean hands and lips. But having been washed, we may enter God's presence.
The pattern of our liturgy follows the basic Biblical structure of sacrificial worship. This pattern is found in both old and new covenant Scriptures, but perhaps the easiest place to see this shape is in Leviticus 9, the first time corporate worship was offered at the newly constructed tabernacle. We are fully warranted in using this pattern in the new covenant. While Jesus abolished animal sacrifice, he did not revoke the way of sacrifice (e.g., Rom 12:1-2, Heb 13:15, etc.). New covenant worship is still described in sacrificial categories, and the church is described as the true temple. In Christ, our worship service represents the fulfillment and transformation of old covenant liturgical types and shadows. Our worship service is as follows:
(Lev 9:5) Our worship is a response to God's summons. He always takes the initiative. We draw near only because He first invites us.