Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Sacred Heart (also known as Sacred Heart of Jesus) is one of the most famous religious devotions to Jesus's physical heart as the representation of His divine love for Humanity. This devotion is predominantly used in the Roman Catholic, Anglo Catholic, and Lutheran Churches. It stresses the central Christian concept of loving and adoring Jesus. The origin of this devotion in its modern form is derived from a French Roman Catholic nun, Marguerite Marie Alacoque, who said she learned the devotion from Jesus in visions. Predecessors to the modern devotion arose unmistakably in the Middle Ages in various facets of Christian mysticism.