Divine Mercy Revelations to St. Faustina

Beginning February 22, 1931, Jesus appeared to Faustina with two rays of light (red and white) from his heart, instructing her to commission an image bearing the words "Jesus, I trust in You" and establish a Feast of Divine Mercy. Over 1931–1938 she received the Chaplet of Divine Mercy and over 600 pages of recorded visions and locutions. The devotion was approved and Divine Mercy Sunday established for the universal Church at her canonization in 2000.

On the night of February 22, 1931, Sister Faustina Kowalska was in her cell at the convent in Płock, Poland, when she saw Jesus standing before her clothed in white. From his heart, two rays of light extended outward — one red, one white, representing, she was told, the blood and water that had flowed from his side on the cross. He instructed her to have an image painted of this vision and to have written beneath it the words "Jesus, I trust in You." He asked for the establishment of a Feast of Divine Mercy on the Sunday after Easter, and promised extraordinary graces to those who approached the sacraments on that day with trust in God's mercy.

This was the beginning of a series of mystical experiences that continued for seven years, across three convents and under the spiritual direction of several priests, most significantly Father Michał Sopoćko in Vilnius. In 1935, Faustina received the Chaplet of Divine Mercy — a prayer sequence said on rosary beads — which Sopoćko helped her commit to writing. She also recorded visions of heaven, purgatory, and hell; detailed instructions for the image and the feast; and an account of Jesus commissioning her as the "Secretary of Divine Mercy," tasked with making his mercy known to the world.

She wrote all of it down. The diary grew to more than six hundred pages of careful, sometimes vivid prose, written in the ordinary notebooks of a working sister over years of illness, doubt, and opposition from those around her. She was not a theologian, had no formal education beyond what the convent provided, and was frequently dismissed by those who found her claims implausible. She accepted this without apparent bitterness.

After her death in 1938, the diary circulated among Polish clergy. In 1959 it was placed on a Holy Office restricted list, principally due to concerns about errors in Italian and French translations. A thorough theological review of the original Polish text, undertaken by Polish bishops, found no doctrinal problems. The restrictions were lifted. Pope John Paul II, who had encountered Faustina's spirituality during his years as a priest and then bishop in Kraków, became the central figure in rehabilitating and promoting the devotion. He beatified her in 1993 and canonized her in 2000. At the canonization, he formally established Divine Mercy Sunday for the universal Church — fulfilling in the official liturgical calendar what Faustina had first written down in a Polish convent notebook sixty-nine years earlier.