Why did He record it in Genesis, then, and refer to it regularly throughout the Bible? Merely as an allegory?
It was not written as an allegory. It follows a strict historical narrative style. It is the same historical narrative style that gives the genealogies, lists the battles and kings, tells the history of the exodus, and details the lives and adventures of the patriarchs.
The story of creation is allegory, and confusing Exodus and the later books of the with Genisis is rather amusing as well. You are correct much of the bible tells historical lineages. However to extrapolate that the story of exodus is historical and literal that the story of creation is also literal is a giant leap of nonsense.
God created the universe and all that is in it, then this creator created us, and while we are told we are the chosen of God, we are certainly not God, and we are told the story of creation, you believe that the story would not need to be insanely simplified to be comprehended by a man who had no more knowledge of this universe at the time than what he could see with his naked eye? This is nonsensical.
Man has walked the earth for 10s of thousands of years, our understanding of the natural world is far beyond that of those at the time of the writing of the Bible and through all still could not remotely understand the creation of the universe if God were to speak to us in human form today.
Do you even know how the Bible came to be the Bible? God did not plop it down written and complete, man wrote the words of the Old Testament, and a communion of men chose which texts would be included and which would not. Since its original conclusion of the included texts, break offs have decided to remove texts from their versions, and add others, etc etc etc.
The fact that later books in the bible reference Genesis as proof of historical fact is interesting, if disingenuous. Pleanty of references back to known literature occur throughout time, does that mean the works referenced prior are not allegory or fiction? I do not say Genesis is fiction, but the creation story it is allegory.
The earth did not appear out of nothing instantly within a few dozen hours, cooled, vegitated, supporting life as we know it, covered in water. The moon did not appear within a few hours either. Those that claim literal interpretation of every word of the Bible, rather than recognizing where allegory are clearly being used do no service to God or man.
You presume that to recognize allegory is to call God a liar, when no such charge has been made. You presume to know God’s will to say that he would not use such a device to commune with his creation.. and that’s a bit too hubris to believe.