Genesis reveals how people can have a relationship with God. This comes through trust in God and obedience to Him. Faith is the key word in Genesis. God proves Himself faithful in this book.
Exodus reveals that God is also sovereign. He is the ultimate ruler of the universe. The sovereign God provided redemption for people so they could have an even deeper relationship with Himself. Man's response should be worship and obedience.
Leviticus reveals that God is also holy. He is different from people in that He is sinless. The proper human response to this revelation of God's character is worship on the part of sinners. In order for a holy God to have a close relationship with sinful people someone must do something about sin. This is true even in the case of redeemed sinners. Atonement is the solution that God provided.
The first half of Leviticus reveals the laws that the Israelites had to observe in their public life (chs. 1-16). These included laws concerning sacrifices (chs. 1-7), the priesthood (chs. 8-10), and the means of purification from various defilements (chs. 11-16).
The second half of the book reveals God's provisions for the maintenance of covenant fellowship in private life (chs. 17-25). This involved holiness of conduct by the people (chs. 17-20) and the priests (chs. 21-22) in all their time (ch. 23), their worship (ch. 24), and their land (ch. 25).
The book closes with God formally exhorting the nation to obey and remain faithful to the covenant that He had established (ch. 26). He also gave directions concerning the vows His people would make out of devotion to Him (ch. 27).
Leviticus focuses on priestly activity, but it is also a great revelation of the character of God and His will to bless people. In it God's people can learn what is necessary for sinners, even redeemed sinners, to have an intimate relationship with a holy God. These necessities include sacrifice, mediation, atonement, cleansing, purity, etc. This revelational value of the book continues even though its regulatory value (i.e., how God's people were to behave) ended with the termination of the Mosaic Law (cf. Mark 7:18-19; Acts 10:12; Rom. 7:1-4; 10:4; 14:17; 1 Cor. 8:8; Gal. 3:24; 4:9-11; Col. 2:17; Heb. 9:10).
