Catholic devotion to the Cor Jesu - Heart of Jesus - has existed in one form or another for many centuries. The human heart is often associated with love, but this is symbolic rather than physiological. Because of His love for us, however, the crucified Christ received an actual physical wound in His Heart when His side was pierced and "blood and water flowed out" {John 19:34}. The wound was deep, but His mercy is much deeper. This wounded Heart is thus a much more profound sign of true love than any heart found on Valentine cards and candy. 

The early Fathers and Doctors of the Church often wrote of the merciful love of Jesus, and referred to the wound in His side as "the open treasury of all graces." By the 10th century, devotion to the wound in Jesus' Heart was being fostered by the Benedictine and Cistercian orders. Franciscans and others later spread devotion to the 5 wounds of Christ on the cross, with a special emphasis on the Heart wound. Saints and mystics often spoke of "hiding" and "taking refuge" in this opening. St. John Eudes {feast: August 19} wrote a book of devotions to the "Adorable Heart of Jesus" in the mid-1600s. 

The most famous and widespread devotion to the Heart of Jesus, however, began after the apparitions of our Lord to St. Margaret Mary Alacoque, which is the subject of this window. The saint can be seen kneeling in prayer, dressed in the habit of the Visitation Sisters. Christ appears to her within a mandorla nimbus surrounded by angels, showing her His Sacred Heart. A detailed carving of this Heart may be seen on the front of the marble altar below and to the left of this window. 

Margaret Mary was born at Terreau in Burgundy on July 22, 1647. In 1671 she entered the Order of the Visitation, founded by St. Jane Frances de Chantal, and she professed the following year. After she had been purified by many trials, Jesus appeared and exposed His Heart to her in numerous visions as she knelt before the Tabernacle in her convent at Paray-le-Monial, France. His Heart was afire, "burning with love for mankind", but it was also torn and bleeding on account of the world's sins and rejection of Him. Our Lord made many promises in favor of those who would honor His Heart. To those who would receive Holy Communion on the first Friday of nine consecutive months, the Savior promised, "I will be their assured refuge in their last moments." In 1675 Christ gave Margaret and her spiritual advisor, St. Claude de la Colombiere, the mission of spreading devotion to the Sacred Heart around the world, and seeking the institution of a feast in its honor by the Universal Church. 

Father de la Colombiere worked zealously to make the mercy of the Heart of Christ known. In 1676 he went to England as chaplain to the Duchess of York, but was arrested two years later, falsely accused of taking part in a "Popish plot" to overthrow the Anglican royalty. After spending some time in prison, he was sent back to France. His health broken by this ordeal, he died at Paray-le-Monial in 1682. He is honored by the Church on February 15. Margaret died in 1690, and her feast is October 17. 

A limited feast day for the Sacred Heart was approved in 1765 by Pope Clement XIII. Pope Pius IX later extended this feast to the whole world. The Jesuits formed the Apostolate of Prayer in 1861 to spread the devotion, and three years later the canonization process began for Margaret Mary Alacoque. The devotion grew rapidly during these years, with the praying of Litanies, First Friday Masses, and the consecration of individuals, dioceses, and eventually entire nations to the Sacred Heart of Jesus. The Feast of the Sacred Heart is celebrated on the Friday following the Feast of Corpus Christi. 

Many St. Martin's parishioners have joined in the growing world-wide devotion to the Divine Mercy, which is based on the revelations of Christ during His apparitions to a Polish nun, Saint Faustina Kowalska, beginning in 1931. This devotion uses different prayers than the Sacred Heart devotion, but is nonetheless an appeal for mercy to the same Heart which was pierced for men. St. Martin's parish has a life-sized icon of the Divine Mercy image, which stands beneath window 2N. Based on the painting that Faustina had commissioned of her vision, this icon shows two rays, one red and one white, coming forth from the Heart of Jesus. These represent the Blood and Water which flowed from the Savior's side after He was pierced on the Cross. Our parish is honored to have in its possession a relic of St. Faustina, who was canonized by Pope John Paul II during the Jubilee Year of 2000. The relic is kept beneath glass on a kneeler in front of the Divine Mercy image. 

Near the Sacred Heart window (on a stone pedestal beside a grand piano) is a bronze bust of St. Teresa Benedicta of the Cross, which was commissioned by the late Father Vernon Robertson, former pastor of St. Martin's. St. Teresa Benedicta was a Carmelite nun who was martyred by the Nazis at Auschwitz during World War II. Born Edith Stein and raised as a Jew, she became a feminist and philosopher. After her conversion to the Catholic faith, she wrote the following about the Sacred Heart: 

Some of today's Catholic writers have compared the Sacred Heart - the "furnace of love" - with Purgatory, the state of purification for souls after the death of the body. Former thinking of this state had emphasized only its pains, making Purgatory seem to be an adjunct of Hell. Purgatory is now more properly emphasized as an anteroom to Heaven, where despite the pains, salvation-assured souls actually desire to be purified so they may enter into the presence of God without the stain of their sins. Thus, some Catholic thinkers write, the purifying fires of Purgatory are much more like the loving fire of Jesus' Heart than they are like the fires of Hell. 

- Latin hymn, 18th century 
                          translated by Edward Caswall (1814-1878) 

- From the Paris Breviary (1736)