If we start from the beginning, reading the story of the creation of the world, not as a historical manifesto, but rather as an indicative story of the way in which all human beings fall from grace, and are in need of restoration, we will soon find ourselves relieved from the albatross of proof.
Much has been written in recent years about absolute proofs for the historicity of the Bible, and the trustworthiness of its message based on provable facts. And while those apologetic arguments are important [and many of them factual], our postmodern world has freed us to recover the story of Scripture. If we read the Bible as true myth [which in no way denigrates the usefulness, or inspiration of Scripture], we see less need to prove the historicity of the story and can then instead focus our attention on the inherent truths of that story.
Scot McKnight points out in his book Embracing Grace
The gospel is good enough on its own, and it doesn't need to be propped up with proofs. Stories are like that. No one needs to prove that The Adventues of Tom Sawyer or The Lord of the Rings or Charlotte's Web are good stories. Read them and you will be drawn in, just as we can be drawn into the gospel story.
How would our understanding of the Genesis story change if we read it simply as a story without the constant worry about extricating historical truths from its pages, and instead viewed the narrative as the story of how human beings created in the image of God crack that image, and are in need of restoration. I am once again not denying its historicity, or the truth of the story. If anything I would say that this reading makes the story even more truthful [I would like to insert the made up word truthfuller somewhere here]
If the gospel story begins in Genesis 1, maybe we should be reading the Scriptures as a story, and not a contract made between God and man.