It is largely debated in scholarly circles, and largely believed in popular circles that the first five books of the Bible were written by a group of unknown scholars. This theory is called the Documentary Hypothesis. Because it is not our purpose here to debunk such a view (it’s already been debunked here) I’ll simply state that the Church historical has always held the Documentary Hypothesis to be wrong, and to stand within the historic orthodox Christian position means one sees Moses as the author of the first five books of the Bible.
Now that we’ve accepted Mosaic authorship of the first five books of the Bible, two questions come to us concerning Genesis. When and why did Moses write Genesis?
Moses wrote Genesis sometime during the Israelite Exodus from Egypt or the Israelite wandering in the wilderness. As for why Moses wrote it we again need to remember what we’ve already said. Rather than analyzing Genesis with a view to 21st century scientific questions, we should analyze Genesis within the religious and theological context of the Israelite Exodus and wilderness wandering. If seen in that light we then understand a different meaning behind both the creation account and the book as a whole.
Israel had left Egypt, a land given over to idolatry and paganism. They were preparing to enter into the promise land, a land currently occupied by idolaters and pagans. Genesis would have been a great encouragement to Israel because Genesis begins with God’s people (Adam and Eve) being safe in Eden while Genesis ends with God’s people (Israel) safe in Egypt. Even though Genesis 3-49 is a horrid, wicked, and a sinful family history, God is still leading His people to where He wants them to be. This would’ve comforted the wandering Israelites as they were headed into the unknown promise land.
This also serves to be a great encouragement for the Church, because as Israel was wandering throughout the wilderness toward a promised land, so too the Church is sojourning as aliens in this present world, waiting for God to come and fully usher in the age to come when we will cross the greater ‘Jordan river’ and enter into the greater ‘Canaan.’ Just as God brought Israel to the promised land, so too will He bring the Church to glory.
…Genesis 1:1 tomorrow