In her Diary, St. Faustina records a special promise given to her by Jesus. He told her to communicate it to the whole world:
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. I pour out a whole ocean of graces upon those souls who approach the fount of My mercy (699).
In three places in her Diary, St. Faustina records our Lord’s promises of specific, extraordinary graces:
I want to grant a complete pardon to the souls that will go to Confession and receive Holy Communion on the Feast of My mercy (1109). Whoever approaches the Fountain of Life on this day will be granted complete forgiveness of sins and punishment (300). The soul that will go to Confession and receive Holy Communion will obtain complete forgiveness of sins and punishment (699)