I find it ironic that atheists are strongly arguing that the Bible must be interpreted literally, even though it's been interpreted allegorically ever since church father Origen, probably before him even.
Atheists WANT the Bible to be interpreted literally so they can have something to attack.
If it's a symbolic parable or allegory, atheists have nothing left to attack.
Quote from Wikipedia.com :
Some Jews and Christians have long considered the creation account of Genesis as an allegory instead of as historical description, much earlier than the development of modern science. Two notable examples are Augustine of Hippo (4th century) who, on theological grounds, argued that everything in the universe was created by God in the same instant, and not in six days as a plain account of Genesis would require;[2] and the 1st century Jewish scholar Philo of Alexandria, who wrote that it would be a mistake to think that creation happened in six days or in any determinate amount of time.[3]