(from www.thedivinemercy.org) 

 The message of The Divine Mercy is simple. It is that God loves us – all of us. And, He wants us to recognize that His mercy is greater than our sins, so that we will call upon Him with trust, receive His mercy, and let it flow through us to others. Thus, all will come to share His joy.  

 This message and devotion to Jesus as The Divine Mercy Himself is based on the writings of Saint Faustina Kowalska, an uneducated Polish nun who, in obedience to her spiritual director, wrote a diary of about 600 pages, recording the revelations she received about God’s mercy.  

 The most comprehensive revelation can be found in her Diary entry 699, where the Lord Jesus expressed His will to have a special feast day for Divine Mercy: 

My daughter (Sister Faustina), tell the whole world about My inconceivable mercy. I desire that the Feast of Mercy be a refuge and a shelter for all souls, and especially for poor sinners. 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 are opened all the divine floodgates through which graces flow. 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. Everything that exists has come from the very depths of My most tender mercy. Every soul in its relation to Me will contemplate My love and mercy throughout eternity. The Feast of Mercy emerged from My very depths of tenderness. It is My desire that it be solemnly celebrated on the first Sunday after Easter. Mankind will not have peace until it turns to the Fount of My mercy. 

With this revelation, Saint Pope John Paul II declared every Second Sunday of Easter to be “Divine Mercy Sunday”.