Did you know that the Book of Genesis is background story to the Book of Exodus?
The point of Genesis for the Israelites was to give them a history, to explain how they ended up in Egypt.
The nation of Israel did not exist until they left Egypt (which is called an exodus...hence the name of the book). The book of Exodus is the story of Moses leading the twelve tribes of Jacob (whose other name is Israel) out of Egypt, of Moses leading the exodus out of slavery into the promised land.
Tradition teaches us that Moses wrote the first five books of the Old Testament, the first five books are called the Torah. Torah is a Hebrew word that can have several translations depending on the context. A good word to use is "instruction", the purpose of the first five books was to instruct the nation of Israel about their God, their calling, their purpose, their history (mistakes and victories) and to forge an identity for them.
The book of Genesis clearly describes God as the sole source of the nation of Israel: he creates Adam and Eve, and from Adam and Eve come Seth, and from Seth (you can trace the many geneologies provided in Genesis) comes Noah, and from Noah comes Shem, and from Shem comes Abraham and from Abraham comes Isaac and from Isaac comes Jacob and from Jacob comes the Twelve Tribes, and from the Twelve Tribes comes Moses and the nation of Israel. We have Genesis so we know where Moses came from, how the Israelites got to Egypt. The Exodus is the birth place of the nation of Israel. Genesis is the pre-history of Israel. So when you read the first 9 chapters, you're reading ancient history. The point of the stories about Creation, Adam and Eve, Cain and Able, Lamech, the Flood, Babel is not so much the truth of the stories (it is very valuable to read them as true), the stories are stories which help explain why the world is the way it is, and for Israel, they are the foundational stories for how they got to where they are, and why they are to do what they are called/created to do.
Hope this background information helps. Feel free to ask for clarifications, post questions or make comments.
There's more background to this Genesis story...check the next post later today...or tomorrow...