by C.S. Lewis. No contest. Thoughts at the link. Quoted below:
"I read this years ago and did not grasp it. But I felt I’d just read Lewis’ most mature artistic work. Reading it as the person I am now, Till We Have Faces made me ache. Ache with beauty. Ache with grief. Ache with love. Ache with awe.
Lewis drew me deep into the heart of the protagonist where I felt her every joy and enumerable sorrows. Many pages were read through tears. This is a beautiful retelling of the Greek tragedy of Cupid and Psyche from the sister’s point of view. And through Orual’s eyes, Lewis crafts a deep, rich meditation on the nature of love, holiness, man, and gods.
For Orual, holiness is known to her as darkness and the stench of blood. For me, holiness is this book."