"Jesus, I Trust in you" is the essence of the message that St. Faustina received. In repeated revelations to St. Faustina, Our Divine Savior makes it clear that the fountain is His Heart, the water is His Mercy, and the vessel is His Trust.
Promises of the Chaplet of Divine Mercy
(words by Jesus to Saint Faustina)
I desire to grant unimaginable graces to those souls who trust in My mercy. ( Diary of Saint Faustina, 687 )
My daughter, encourage souls to say the chaplet which I have given to you.
It pleases Me to grant everything they ask of Me by saying the chaplet. ( Diary of Saint Faustina, 1541 )
When this chaplet is said by the bedside of a dying person... unfathomable mercy envelops the soul,
and the very depths of My tender mercy are moved for the sake of the sorrowful Passion of My Son.
"I have opened My Heart as a living fountain of mercy.
Let all souls draw life from it.
Let them approach this sea of mercy with great trust. " (Diary of Saint Faustina, 1520)