For nearly 2,000 years, Christian mystics, martyrs, and sages have documented their search for the divine. Their writings have bestowed boundless wisdom upon subsequent generations. But they have also burdened many spiritual seekers. The sheer volume of available material creates a seemingly insurmountable obstacle. Enter the Upper Room Spiritual Classics series, a collection of authoritative texts on Christian spirituality curated for the everyday reader. Designed to introduce 15 spiritual giants and the range of their works, these volumes are a first-rate resource for beginner and expert alike. John of the Cross, a 16th-century Carmelite monk, used vivid metaphors and biblical stories to describe a process of detachment from earthly desires. His experience, which he described as the "dark night of the soul," freed him to receive God's blessings. John's writings have inspired countless Christians over the centuries.