The Feast of Divine Mercy
Among all of the elements of devotion to The Divine Mercy requested by our Lord through Sr. Faustina, the Feast of Mercy holds first place. The Lord's will with regard to its establishment was already made known in His first revelation to the saint. In all, there were 14 revelations concerning the desired feast.
I want this image to be solemnly blessed on the first Sunday after Easter; that Sunday is to be the Feast of Mercy. On that day, the depths of My Divine Mercy will be open to all.
On one occasion, 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.* [our emphasis] 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. Everything that exists has come forth from the very depths of My most tender mercy. Every soul in its relation to Me will I 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. (Diary 699)
Whoever will go to confession and Holy Communion on that day will receive complete forgiveness of sin and punishment. Mankind will not enjoy peace until it returns to My Mercy.
We should spread this devotion and make it also known to priests so that they may celebrate the Feast of Divine Mercy in honor of Our Lord.
To observe this feast we should commence a Novena to the Divine Mercy on Good Friday, the Novena includes special intentions for each day and is concluded with the recitation of the Divine Mercy Chaplet.
Celebrate the feast on the first Sunday after Easter.
Come to Jesus with a humble and contrite heart, repent of all your sins.
Firmly trust in the Divine Mercy of Jesus.
Go to confession (with a priest) on that day if possible, otherwise seven days before or after the feast, as approved by the Church..
Receive Holy Communion on the Day of the Feast.
Venerate the image of Divine Mercy.
Be merciful as God is merciful. Practice works of Mercy, physically by helping others or spiritually by prayers of intercession.
The Cardinal of Krakow, Cardinal Macharski, whose diocese is the center of the spread of the devotion and the sponsor of the Cause of Sr. Faustina, has written that we should use Lent as preparation for the Feast and confess even before Holy Week!
So, it is clear that the confessional requirement does not have to be met on the Feast itself. That would be an impossible burden for the clergy if it did. The Communion requirement is easily met that day, however, since it is a day of obligation, being Sunday. We would only need confession again, if received earlier in Lenten or Easter Season, if we were in the state of mortal sin on the Feast.
Jesus also requested that the Sunday after Easter be officially established in the Church as the Feast of Mercy: "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."