Saint John of the Cross (1542-1591) was a poet, priest, philosopher, and mystic who helped to bring about reform within the Roman Catholic Church during the sixteenth century. A member of the Carmelite Order, he worked diligently with Saint Teresa of Avila to return their order to its proper foundation, a deep devotion to Jesus Christ. As a result of their efforts, John was imprisoned. Central to Saint John's beliefs are the death of the self-life, the mortification of the flesh, and overcoming the devil, the world, and all temptations so that the soul can be completely united to God and His love.