Saint Margaret Mary Alacoque

Saint Margaret Mary Alacoque

Main article: Margaret Mary Alacoque

The most significant source for the devotion to the Sacred Heart in the form it is known today was Saint Margaret Mary Alacoque (1647–1690), a nun of the Order of the Visitation of Holy Mary, who claimed to have received apparitions of Jesus Christ, the first on 27 December 1673, the feast of Saint John the Evangelist, and the final one 18 months later, revealing the form of the devotion, the chief features being reception of Holy Communion on the first Friday of each month, Eucharistic adoration during a "Holy hour" on Thursdays, and the celebration of the Feast of the Sacred Heart. She said that in her vision she was instructed to spend an hour every Thursday night to meditate on Jesus' Agony in the Garden of Gethsemane.

In probably June or July, 1674, Sister Margaret Mary claimed that Jesus requested to be honored under the figure of his heart, also saying that, when he appeared radiant with love, he asked for a devotion of expiatory love: frequent reception of Communion, especially on the first Friday of the month, and the observance of the Holy hour.
During the octave of Corpus Christi, 1675, probably on June 16, the vision known as the "great apparition" reportedly took place, where Jesus said, "Behold the Heart that has so loved men ... instead of gratitude I receive from the greater part (of mankind) only ingratitude ...", and asked Margaret Mary for a feast of reparation of the Friday after the octave of Corpus Christi, bidding her consult her confessor Father Claude de la Colombière, then superior of the small Jesuit house at Paray.
Father de la Colombière directed Sister Margaret Mary to write an account of the apparition, which he discreetly circulated France and England. After his death on February 15, 1682, his journal of spiritual retreats was found to contain a copy in his handwriting of the account that he had requested of Margaret Mary, together with a few reflections on the usefulness of the devotion. This journal, including the account; an "offering" to the Sacred Heart, in which the devotion was explained, was published at Lyons in 1684. The little book was widely read, especially at Paray. Margaret Mary reported feeling "dreadful confusion" over the book's contents, but resolved to make the best of it, approving of the book for the spreading of her cherished devotion. Besides the Visitandines, priests, religious, and laymen espoused the devotion, particularly the Capuchins. The reported apparitions served as a catalyst for the promotion of the devotion to the Sacred Heart.[14] Jesuit Father Croiset wrote a book called The Devotion to the Sacred Heart of Jesus, and Fr. Joseph de Gallifet, also a Jesuit, promoted the devotion. The mission of propagating the new devotion was especially confided to the religious of the Visitation and to the priests of the Society of Jesus.