Large amounts of the Pentateuch (first five books of the Old Testament), if not all, are believed to have been written by Moses. Leviticus is the third book of five in the Pentateuch. Leviticus continues the theme found in Exodus - that God is holy and his people should be holy too. Leviticus presents a "manual of worship" containing instructions for the ancient priests. The Five Main Offerings (chs. 1–7) The Burnt Offering (ch. 1) The Grain Offering (ch. 2) The Fellowship Offering (ch. 3) The Sin Offering (4:1—5:13) The Guilt Offering (5:14—6:7) Additional Regulations for the Offerings (6:8—7:38) The Installation and Ministry of Aaron and His Sons (chs. 8–10) The Ordination of Aaron and His Sons (ch. 8) The Ministry of the Priests (ch.