G. Van Der Leeuw's Religion in Essence and Manifestation (Vol. I) is a profound study of the phenomenology of religion. It seeks the essence of religious experience, not merely its history or psychology. Van Der Leeuw explores how humans understand the sacred through concrete manifestations and discusses the vertical and horizontal paths between humans and God. Van Der Leeuw focuses on what these phenomena mean to their adherents. This classic work seeks to provide a comprehensive understanding of the structure and meaning of religious experience.