Yes, Hisclarkness has stated the contingency of Christianity. Within the two central laws of Christ lies the foundation: Love God and love your neighbor. NOT a talking snake. Yes, Jesus also talked about that, but in the context of archetypal mythology, as Aha suggests, the Law of Love was understood in the worldview of Hebrew understanding 2000 years ago.
While the archetype of serpent and savior are difficult to nail down, we understand the next chapter of Genesis explains the fall from grace for mankind is somehow tied to the shift in human worldview as pastoral hunter-gatherers were supplanted by a rising agrarian civilization. Abel was considered still close to perfection for offering his prized sheep, but Cain was considered inferior for his offering from the farm.