Our Lord revealed to Saint Faustina a powerful prayer that He wanted everyone to say - The Chaplet of Divine Mercy. St. Faustina prayed the Chaplet constantly especially for the dying, and the Lord urged her to encourage others to say it too, promising extraordinary graces to those who would recite this special prayer.

Our Lord said to Saint Faustina:

Encourage souls to say the Chaplet which I have given you. Whoever will recite it will receive great mercy at the hour of death. ... When they say this Chaplet in the presence of dying, I will stand between My Father and the dying person, not as the just Judge but as the Merciful Saviour. Priests will recommend it to sinners as their 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 to grant unimaginable graces to those souls who trust in My mercy. ... Through the Chaplet, you will obtain everything, if what you ask is compatible with My will.