Those books are not easy reads....and yet, as i ground through them, I found it fascinating, knowing that Lewis was once an agnostic and yet converted to Christianity (yes I know he was originally baptized and fell away). The book that influenced me most was to read about his religious passion as he watched his wife die in A Grief Observed. Every so often I’ll pick up one of his books and read or reread things I read years ago that really are thought provoking.
Go read his Space Trilogy: Out of the Silent Planet, Perelandra, That Hideous Strength