On Sunday, April 24, the Catholic Church celebrates Divine Mercy Sunday, a feast that was established because of a request that Jesus made to a young Polish nun in the 1930s.
The feast, and the Divine Mercy image of Jesus dressed in a white robe, with rays of red and white light streaming from his heart represent the fulfillment of Maria Faustyna Kowalska's mission. As a young Polish nun in the 1930s she began to be experience visions of Jesus. He instructed her to have the Divine Mercy image made and to share it with the world in order to make his message of infinite love known.
If that piques your interest, you can learn more about the fascinating story behind Divine Mercy Sunday by watching the 2019 documentary Love and Mercy. The movie chronicles St. Faustina's successful struggle to convince others of the truth of her story. Pope St. John Paul II, later championed her cause for the sainthood, and declared the Sunday after Easter "Divine Mercy Sunday."
Love and Mercy is available to view for free here.