Write down everything that occurs to you regarding My goodness. I answered, "What do You mean, Lord, what if I write too much?" And the Lord replied, My daughter, even if you were to speak at one and the same time in all human and angelic tongues, even then you would not have said very much, but on the contrary, you would have sung in only a small measure the praises of My goodness-of My unfathomable mercy.
O my Jesus, You Yourself must put words into my mouth, that I may praise You worthily.
My daughter, be at peace; do as I tell you. Your thoughts are united to My thoughts, so write whatever comes to your mind. You are the secretary of My mercy. I have chosen you for that office in this life and the next life. That is how I want it to be in spite all the opposition they will give you. Know that My choice will not change.
At that moment I steeped myself in profound humility before God's majesty. But the more I humbled myself, the more God's presence penetrated me...  WORDS OF JESUS TO ST. FAUSTINA  (Diary, 1605)