Genesis is the first book of the Pentateuch and is best understood in light of the Pentateuch as a whole. The Pentateuch is comprised of the five books of Moses—Genesis, Exodus, Leviticus, Numbers and Deuteronomy—and was probably written between 1445 and 1406 BC. Of these five books, the legal and ceremonial portions of Exodus and Leviticus probably were written first, shortly after the Exodus of God’s people from Egypt and Israel’s sin with the Golden Calf, since the complexity of the code and the rituals Israel was commanded to follow would have necessitated having it in writing. Indeed, the first mention in Scripture of anyone writing anything comes in Exodus 24:4, when Moses writes down the words of God at Sinai after giving the people the Law which God gave Him. Deuteronomy, the culmination of the covenant, was probably written at the end of Moses’ life in 1406 BC, as the people were poised to enter the land which God had promised them in His covenant with Abraham. The account of Moses’ death in Deuteronomy 34 was probably written by Moses’ deputy and successor, Joshua and appended to Deuteronomy. Deuteronomy is written in the form of an ancient Near Eastern covenant or treaty, in this case a covenant between God and His people. The covenant would have facilitated the transition of leadership from Moses to Joshua, but in doing so Moses also probably was intended to show the Israelites that the ultimate leader to whom they owed allegiance was God Himself. The narratives in Genesis, Exodus and Numbers provide the connective tissue that situate these legal and ceremonial codes.
In the combined narrative that is the Pentateuch, Moses lived through the events covered by the books of Exodus, Leviticus, Numbers and Deuteronomy; the events covered by Genesis, however, covers the period from the creation of the world until four hundred years before Moses’ birth. In writing Genesis, Moses probably drew on traditions handed down from generation to generation, corrected and supplemented as a result of his personal interaction with God directly during the years of Israel’s wandering in the wilderness. Because the narrative gap between Genesis and Exodus is seamless, the omission of any history of the Israelites between the death of Joseph and the birth of Moses is almost certainly deliberate. In the narrative that Moses presents in the Pentateuch, the focus is on God’s deliverance of His people in the Exodus, which was the seminal salvation event of the Old Covenant (i.e. Old Testament). Read in light of Deuteronomy, the Pentateuch shows that the identity of God’s people is centered in His work of salvation in the Exodus, which is rooted in His unbreakable covenantal commitment to them and is extended to them wholly by His grace. Genesis describes those earlier covenant promises that were to be fulfilled in the Exodus, and thus can be read as a kind of prequel to the Exodus. The promises in Genesis associated with God’s people coming into the land find their fulfillment in the narrative about the Conquest recounted in Joshua.