From Sr. Faustina's Diary: Jesus' Promise on His Feast of Mercy:
"Once, as I was going down the hall to the kitchen, I heard these words in my soul:
Say unceasingly the chaplet that I have taught you. Whoever will recite it will receive great mercy at the hour of death.
Priests will recommend it to sinners as their last hope of salvation.
Even if there were a sinner most hardened, if he were to recite this chaplet only once, he would receive grace from My infinite mercy. I desire that the whole world know My infinite mercy.
I desire to grant unimaginable graces to those souls who trust in My mercy.
I heard these words:
"My daughter, tell the whole world about My inconceivable Mercy. I desire that the Feast of Mercy be a refuge and 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 all the divine floodgates through which graces 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.
Everything that exists has come forth 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. "
This year's Feast of the Divine Mercy is on April 23.