My brother and I have this debate all of the time. I see it as a tool for debate. If the first part of the bible is an allegory, or it isn't factual, then there could be other parts of the scriptures that also are not factual, i.e. Jesus is the Way, and the Truth, and the Life. So, for that reason alone I would declare the Word of God completely factual and completely true. Now, because it was written down from oral traditions, and it was meant to be understood by shepherds and farmers, it may have been simplified, but that is my humanly perspective. My faith in God as an all powerful being is such that I believe that every single word was placed in it's exact position because that is how God wanted it to read for His divine purposes. Does it change the Salvation of Jesus Christ either way, no, but it does make for some fun debate.