Devotion to the Immaculate Heart of Mary dates back to at least the Middle Ages, and has been promoted by a wide variety of saints, always alongside a devotion to the Sacred Heart of Jesus. The devotion to the Sacred Heart focuses on reparation for Jesus' suffering and gratitude for his merciful love, while a devotion to the Immaculate Heart is focused on a desire to emulate the love, devotion, and obedience of Our Lady. Pope Pius XII instituted the...