It is Tolkien's adept ability at combining imagination with Sub-Creation to give his fictional world of Middle-Earth that ‘inner consistency of reality’ which points to the truth of the Gospel.
Paul's conversion is a death and resurrection story. And in reality, so is every conversion, whether it was an awe-inspiring experience like Paul's or not. Dead to sin and alive in Christ.
Every child builds. Some build castles out of wooden blocks handed down from an older sibling. Some construct forts out of blankets, chairs, and miscellaneous living room artifacts.
God wired us to be storytellers. God made man in his own image and that image includes a rational mind that communicates in large part through stories.