Saint Faustina's Diary contains at least fifteen passages in which our Lord is quoted as requesting that a "Feast of Mercy" be officially established in the Church. Jesus declared:
"This Feast emerged from My most tender Pity and it is confirmed in the depths of My Mercy. I desire that it be celebrated with great solemnity on the First Sunday after Easter.
I desire that the Feast of Mercy be a refuge and shelter for all souls, and especially for poor sinners. The very depths of My tender Mercy are open on that day. I pour out a whole ocean of graces upon souls who will approach the fount of My Mercy."
To the solemn celebration of the Feast, Jesus attached an extraordinary promise:
"The soul that will go to Confession and receive Holy Communion on that day, shall obtain complete forgiveness of sins and punishment. Let no soul fear to draw near to Me, even though its sins be as scarlet."
Jesus requested that Saint Faustina prepare herself for the Feast of Mercy by making a Novena which was to begin on Good Friday, saying:
"I desire that during these time nine days you bring souls to the fount of My Mercy, that they may draw there from strength and refreshment and whatever grace they need in the hardships of life, and especially at the hour of death.
On each day, you will bring to My Heart a different group of souls and you will immerse them in the ocean of My Mercy, and I will bring all these souls into the house of My Father.
You will do this in this life and in the next. I will deny nothing to any soul whom you will bring to the fount of My Mercy.
On each day, you will beg My Father on the strength of My bitter passion for graces for these souls."