Nota bene (That's Latin. It means "note well."), I'm not saying that I believe that Noah built an ark and saved all those animals, or that Samson killed all of those people with the jawbone of an ass. I'm saying that the authors of the Bible, and ancient Jews and Christians, and also most Jews and Christians and Muslims until pretty recently, believed those things happened. Of course, the fundies still believe it. But there has emerged this other group within these religions which still believes in God, and still believes that the Bible is the most important book in the world, but not only no longer themselves believe things like the stories of Noah actually happened, but also are insisting, not only with straight faces but also with advanced degrees in theology and sometimes, unfortunately, in other fields as well, such as Biblical Studies or even ancient history in general, that those stories were ORIGINALLY WRIITEN AND UNDERSTOOD as metaphors, and that literalism and fundamentalism are aberrations from the main traditions of these religions, when, in plain fact, they are not aberrations but holdovers, continuations of the old beliefs.
Where does this recent belief in the non-literal intent of the Bible authors come from? Like other irrational religious beliefs, it comes from an unwillingness to face certain realities. In this case it's an unwillingness to see the ancient world for what it was, the unwillingness to see the similarities between the Abrahamic religions and other ancient beliefs, and the unwillingness to see how much primitive ancient mentality has been brought into our own time by those religions.
Some people believed that Hercules actually existed before Christianity came into the Graeco-Roman world and stomped all over the local religions of which the tales of Hercules and Zeus and Athena and Hermes were a part. In the case of metaphors and fiction, it's clear to both the authors and the audience that the stories are made up. Not so in the case of myths and religion. The Greeks and Romans, many or most of them, believed that lightning and thunder were giant spears hurled by Zeus (whom the Romans called Jupiter), that when the seas became stormy it was because Poseidon (Neptune to the Romans) was agitated, that Aphrodite (the Roman Venus) looked after people in love, and so forth. The Greeks and Roman pagans were much more tolerant when it came to open discussion of religion than were the Christians who wiped their religions out, and so every now and then an ancient Greek or Roman philosopher would express his opinion that all the stories about the gods were nonsense and that no rational person should believe they existed -- but these philosophers were expressing minority opinions, they were going directly against the grain of their society at large. There's no reason to believe that most pre-Christian Romans and Greeks didn't believe in the literal existence of many, many gods and goddesses. The city of Rome in particular was famous as home to a vast number of religions collected from all over the Empire, and many individual Romans each worshiped many different deities. Some of them worshiped Jesus along with many other deities, before Christian authorities made it very plain that to properly practice Christianity meant no longer worshiping deities of any other religions, and, in the late 4th and early 5th centuries, destroyed the many temples of other religions which stood all over the Empire.
There's no RATIONAL reason to believe that the tales of the supernatural in any ancient religions, including Judaism, Christianity and Islam, began as anything other than stories which were believed to be literally true. An irrational reason to believe that they began as fiction and metaphor, with everyone understanding that's what they were, is to deny the distance between the literal belief in them on the one hand and modern knowledge of how the world works on the other, and to insist that the Bible and the Koran are full of "timeless wisdom," and do not merely reflect the worldview of people who believed -- really, literally believed -- that what happened to them was the result of the actions of a huge supernatural Being, and that angels, actual winged angels, watched over us, and that after we died we would be judged and sent to a paradise to live in joy forever or to a pit to be tortured forever, a pit run by an evil angel who'd been expelled from the paradise, and so forth. It's as clear as can be that the founders of these religions and the authors of these holy texts literally, unmetaphorically believed all of that, just as the Graeco-Roman pagans literally believed that their gods lived on Mount Olympus and frequently came down in disguise from the mountain to take part in human affairs. One thing which these ancient books actually can tell us is how far we've come in our understanding since the time when they were written.
That is, of course, some of us. Clearly, others can't get through a single day without making things up. Luckily for very many of them, today just as thousands of years ago, religion offers them jobs.