The OP asked me to post in this thread about the indulgences for DM Sunday so I will try to do that.
One should note that for Divine Mercy (DM) Sunday, there are actually TWO different spiritual benefits you can get:
- Special graces bestowed by Jesus in his promise to St. Faustina, which is private revelation, and comes directly from Jesus. He has promised to grant you a “complete pardon” from sin. To get this special grace, you just need to go to Confession within some reasonable time before DM Sunday (even during Holy Week) and then in a state of grace receive Communion on DM Sunday.
Because this is coming straight from Jesus, it is similar to the promises attached to other devotions that have come to us through private revelation, such as Nine First Fridays and Five First Saturdays.
- Also, completely separate from Jesus’ promise, the Church through its authority has provided for a plenary indulgence for DM Sunday. Note that this is coming from the Church and operates like other plenary indulgences in that you can keep the plenary for yourself or assign it to a deceased soul in Purgatory, such as your loved one who has died.
To get this plenary indulgence, you need to fulfill the usual conditions for a plenary indulgence, which are
- go to confession within 20 days of DM Sunday
- be in a state of grace on DM Sunday
- receive Holy Communion, either on DM Sunday or within a couple days of it
- recite (out loud) prayers for the intentions of the Holy Father - no specific prayers are called out, but usually one says an Our Father, Hail Mary and a Glory Be, out loud
- have no attachment to sin, even venial sin
AND do one of these two indulgenced works on Divine Mercy Sunday - either one will work, but you can only get one plenary indulgence so if you do both, you don’t get extra. Choose from:
Work #1: On Divine Mercy Sunday, in any church or chapel, in a spirit that is completely detached from the affection for a sin, even a venial sin, take part in the prayers and devotions held in honour of Divine Mercy
OR
Work #2: On Divine Mercy Sunday, in the presence of the Blessed Sacrament exposed or reserved in the tabernacle, recite the Our Father and the Creed, adding a devout prayer to the merciful Lord Jesus (e.g. Merciful Jesus, I trust in you!"). If you cannot get to church because you are sick, you are caring for a sick person, you are in the middle of a war or disaster, or are a sailor at sea, then you can also get the indulgence by saying these prayers in front of a Divine Mercy Jesus image wherever you are.
Note that you can use the same Holy Communion and Confession to meet the requirements of Jesus’ promise and the requirements for the plenary indulgence.
And since you can get for yourself the benefit of Jesus’ promise, it is a nice thing to give the plenary indulgence to a poor soul in purgatory, such as a deceased relative, and just have the trust for yourself in the grace from Jesus.
I hope this is helpful and that everyone will take advantage of the opportunity to get all good gifts provided by both Jesus and the Church on DM Sunday.