St. John of the Cross (1542 - 1591) was a Spanish Carmelite Priest and a mystic, or a person who experienced God supernaturally. When he joined the Carmelite Order, the members there were not praying much. Together with St. Teresa of Avila, he reformed the Order, turning it into a house of contemplative prayer. St. John wrote the ‘Dark Night of the Soul’, which explains the different stages of a soul in love with God. He is the patron saint of mystics. His feast day is on 14 December.