Divine Mercy Sunday

Here is information about this Feast:
The Feast of the Divine Mercy or Divine Mercy Sunday falls on the Octave of Easter (the Sunday immediately following Easter)[1]. It is dedicated to the devotion to the Divine Mercy promoted by St. Faustina, and is based upon an entry in St. Faustina's diary stating that anyone who participates in the Mass and receives the sacraments of confession and Eucharist on this day is assured by Jesus of full remission of sins.

According to the notebooks of Saint Faustina, Jesus made the following statements about this day: "On that day the very depths of My tender mercy are open. I pour out a whole ocean of graces upon those souls who approach the fount of My mercy. The soul that will go to Confession and receive Holy Communion shall obtain complete forgiveness of sins and punishment. On that day all the divine floodgates through which grace flow are opened. Let no soul fear to draw near to Me, even though its sins be as scarlet. My mercy is so great that no mind, be it of man or of angel, will be able to fathom it throughout all eternity." (Diary of Saint Faustina, 699)

The devotion was celebrated unofficially in many places for some years. On April 30, 2000 (Divine Mercy Sunday of that year), Pope John Paul II canonized St. Faustina and designated the Sunday after Easter as the Second Sunday of Easter or the Sunday of the Divine Mercy (Dominica II Paschae seu de divina misericordia) in the General Roman Calendar, with effect from the following year. He also decreed a plenary indulgence associated with this devotion. Pope John Paul II said he felt a closeness to St. Faustina when he was writing Dives in misericordia [1]. He died during the vigil of the Divine Mercy Sunday 2005.

I hope this is helpful. I love the Gospel for today that has Jesus appearing to the Apostles without Thomas and then returning to tell Thomas to "Put your finger here and see my hands, and bring your hand and put it into my side, and do not be unbelieving, but believe."