Jesus entrusted Margaret Mary Alacoque with one of the most important missions in the Church: spreading devotion to his Sacred Heart.

Born in 1647 in Hautecour, France, Margaret was devout from childhood. She displayed a deep devotion to the Blessed Sacrament and began practicing corporal mortification after her First Communion. Following a bout of rheumatic fever, she made a vow to the Blessed Virgin Mary to enter religious life.

When Margaret was a teenager, however, her mother pressed her to marry. In obedience to these requests, Margaret attended social events and dressed in fashionable clothing. Jesus, however, wanted Margaret Mary for himself. One evening he appeared, scourged and bloody, and accused her of forgetting him. Margaret, believing she had betrayed Christ by abandoning her promise to the Blessed Virgin, finally entered the Visitation convent at age 23.

In religious life, Margaret Mary continued to receive private revelations that became the basis of the Sacred Heart devotion: Holy Communion on the first Friday of every month; an hour of Eucharistic adoration on Thursdays; and the institution of the Feast of the Sacred Heart. In another vision, Jesus invited Margaret Mary to rest on his heart. He told her of his love for humanity and his sadness at mankind’s ingratitude, asking her to make this message known.

Despite skepticism from within her religious community, Margaret Mary gained her confessor’s support. Over time, devotion to the Sacred Heart spread and the Vatican expanded permissions for the celebration of the Feast of the Sacred Heart. It is now a solemnity observed on the Friday after Corpus Christi Sunday.

Margaret Mary died on Oct. 17, 1690, and was canonized in 1920. Eight years later, Pope Pius XI acknowledged her in his encyclical Miserentissimus Redemptor, calling upon the Church to make reparation to the Sacred Heart of Jesus.