I think we're all cordial enough people that we can discuss this topic without bashing or escalation. Regrettably jason doesn't seem to be active anymore so the forum can't be regulated.
From a narrative perspective, much of the literature that has sprung up exterior to the books of the Bible is interpreted as fictional myth. Dante's Divine Comedy, for example, is an extremely popular piece of religious poetry that rigourously divides Heaven, Purgatory, and Hell into levels of Dante's own design. To my knowledge there aren't any Catholics who openly believe in his complex system of divisions, but the book is embraced as a wonderful allegory of Christian influence on the world in his time.
C. S. Lewis' Chronicles of Narnia openly embrace stories from the Bible as the foundation of its narrative, including Genesis, David and Goliath, Jesus, the Antichrist, and Revelations. Narnia's mythology is developed from Christian allegory, and the books are enormously popular with religious and non-religious people alike.
If anything, Christianity and the other Abrahamic faiths haven't become mythology, but they've created myth, and it's the created myths on which even secular audiences thrive today.
From a comparative mythological perspective, scholars would link some prominent stories in the Bible, such as David and Goliath, the Flood, the dying God, and the End of the World, with similar stories that arose from traditions in cultures which predate Judaism. Those cultures' stories are now interpreted as myth.