Setting aside the question of what Our Lord said to St. Faustina, I have an idea about why we can't wait. John Paul II saw so much of the horrors of the Twentieth Century first hand, I have a feeling that psychologically we can't wait to hear about God's Mercy. That is what we need to hear so desperately. That hit home for me especially this year. Not only is the Church going through a particularly trying time right now, but I've also recently been made more keenly aware of some of the deep personally suffering of people I know. I'm all for the joys of Easter, but this year, I'm more for turning to the Crucified and Risen One for mercy. Perhaps John Paul II felt the same way. Psychological our time is so wounded, so under attack, so down for the count, that almost all we have left is a cry for mercy in the face of enclosing darkness.
Domine Jesu Christe, fili Dei, miserere nobis!