Divine Mercy Sunday is a Roman Catholic solemnity celebrated on the Sunday after Easter, the Octave of Easter. It is originally based on the Catholic devotion to the Divine Mercy that Saint Faustina Kowalska reported as part of her encounter with Jesus, and is associated with special promises from Jesus and indulgences issued by the Church.
This feast of Divine Mercy, as recorded in the diary of Saint Faustina, receives from Jesus himself the biggest promises of Grace related to the Devotion of Divine Mercy. In specific Jesus states that the soul that goes to Sacramental Confession (the confession may take place some days before), and receive Holy Eucharistic Communion on that day, shall obtain the total forgiveness of all sins and punishment. Additionally, the Roman Catholic Church grants a plenary indulgence (observing the usual rules) with the recitation of some simple prayers.
The devotion was actively promoted by Pope John Paul II who, On 30 April 2000, canonized Faustina Kowalska, and officially designated the Sunday after Easter as the Sunday of the Divine Mercy (Dominica II Paschae seu de divina misericordia) in the General Roman Calendar. A year after establishing Divine Mercy Sunday, on April 22, 2001 Pope John Paul II re-emphasized its message in the resurrection context of Easter:
Jesus said to Sr Faustina one day: "Humanity will never find peace until it turns with trust to Divine Mercy". Divine Mercy! This is the Easter gift that the Church receives from the risen Christ and offers to humanity.
The devotion to Divine Mercy Sunday grew rapidly after its designation by Pope John Paul II and is now widely celebrated by Catholics. The Divine Mercy image is often carried in processions on Divine Mercy Sunday, and is placed in a location in the church so that it can be venerated by those who attended the Mass.
The liturgical celebration of Divine Mercy Sunday reflects the devotional elements of Divine Mercy - the first prayer of that Mass beginning with:
"Heavenly Father and God of Mercy, We no longer look for Jesus among the dead, for He is alive and has become the Lord of Life".
This opening prayer refers to Divine Mercy as the key element in the plan of God for salvation and emphasizes the belief that it was through mercy that God gave his only son for the redemption of mankind, after the fall of Adam.
John Paul II, who died in April 2005 on the vigil of Divine Mercy Sunday, was himself beatified on Divine Mercy Sunday, May 1, 2011, by his successor, Pope Benedict XVI.