Below is a clip from a movie about the life of Tolkien (Lord of the Rings guy) and his friendship with CS Lewis (Narnia guy) at Oxford University, where they both met. Tolkien eventually converted Lewis, who as a young man was an avowed atheist, to Christianity.
If you are familiar with Lord of the Rings, you will see a great many inspirations derived from medieval literature. Tolkien in fact was near-fluent in Old English and medieval language, and he understood the "apophatic" nature of existence to the medieval mind.
Watch the clip of an interaction between the young Lewis and older Tolkien, where Tolkien explains to Lewis the medieval understanding of nature and ontology: