Moderate Christians (as opposed to fundamentalists) do not believe that the Bible is necessarily a literal account of historical events. To them, such things as Adam and Eve, Noah, etc. are just stories meant to convey an overall message.
In a video called The Four Horsemen, Sam Harris made a great point. He said that Moderates never admit to how they came to stop taking these stories literally. How is it that they came to be moderate? They have lost faith in the literalism of the text. Just as atheists have no faith in the whole of it.
How can they criticize atheists for not believing in the Bible, when they themselves have stopped believing in it to some degree?