What is the truth that Narnia alludes to? That there are portals to the supernatural all around us for those who have eyes to see.
In a sermon called Weight of Glory, C.S. Lewis said:
“Do you think I am trying to weave a spell? Perhaps I am, but remember your fairy tales. Spells are used for breaking enchantments as well as educing them. And you and I have need of the strongest spell that can be found to wake us up from the evil enchantment of worldliness which has been laid upon us for nearly 100 years”