According to Faustina, Jesus told her that she will pray the Divine Mercy novena in heaven and that he will bring the people she prays for into heaven.
Novena to the Divine Mercy is a Catholic novena composed by Faustina Kowalska in her diary Divine Mercy in my Soul as part of the Divine Mercy devotion.
Each day of the novena consists of praying to God the Father and Jesus for a different group of people - in particular, Catholics - by immersing them in the Sacred Heart.
Practical Novena to the Divine Mercy.
He also told her that, because she would beg for his divine grace for the people in light of his Passion, he would not deny granting the people any of his grace.