From 1931 to 1938 Our Lord revealed the secrets of His great mercy to St. Faustina. 

He designated the first Sunday after Easter as the Feast of the Divine Mercy of God. In preparation of this Feast, He asked that a Novena be started on Good Friday, a Novena which asks for prayers each of the nine days for a different group of souls in order to immerse them in the sea of God’s Mercy!  Mass, Confession, Communion are required on Mercy Sunday, the first Sunday after Easter.

-Our Lord promised to the souls who follow these requests a complete remission of sin and punishment!  Our Lord thus instructed Sister Faustina: “My daughter, speak to the whole world of My incomprehensible Mercy.  I desire that the Feast be a refuge and a shelter for all souls, especially for poor sinners. 

The very depths of My Mercy will be opened on that day.  I will pour out a sea of graces upon those souls that will approach the font of My Mercy.  Those who go to confession and receive Holy Communion on Mercy Sunday, the first Sunday after Easter, will obtain complete remission of sins and punishment.  Let no soul fear to come to Me, even though its sins be as scarlet. 

Tell ailing mankind to draw close to My Merciful Heart and I will fill it with peace.  Mankind will not find peace until it turns with confidence to My Mercy.”