St Faustina, through whom and to whom Our Lord revealed His Divine Mercy, is often referred to as the Apostle of Divine Mercy. As the term Apostle implies, she was sent by Jesus on a mission to spread devotion to God in His greatest attribute which is mercy.
Today's feast is one of trust; Jesus gave St Faustina and us the Divine Mercy prayer, "Jesus, I trust in You." It is also a feast of mission for like Faustina, we too are called by Jesus to be Apostles of His mercy. It is in trusting Him with childlike faith that we can respond to that mission.
In these days of the Easter season, we read from the Acts of the Apostles. We see and hear how the Apostles bore witness to Christ's Resurrection. In doing this they brought more souls to Christ. Jesus is asking the same from us. We who have been shown His mercy are called to give it away to those who are still in need of it.
Maybe this is why Jesus told Mary Magdalene: "Do not hold on to Me" on that first Easter morning. He gave her a mission~ to go and tell the Apostles that she had seen the risen Lord.
Do not hold on to Me; do not hold on to what you have seen or to the gifts you have been given, but go and tell others and share what you have been given.
The gifts God gives us He does not give for ourselves alone. It is all meant to be shared. Like those first Christians who did not keep what they had for themselves, but instead brought all they had and laid it at the feet of the Apostles to be distributed as needed (see Acts 4:32~35), we are asked by Our Lord to lay all we have at His feet so that others may benefit as needed. We do this whenever we practice the corporal and spiritual acts of mercy.
Today's feast of Divine Mercy teaches us to trust in Jesus and it also teaches us how to love our neighbor by sharing all we have been given by our loving and merciful God.