This is the first time that Jesus meets a group of his disciples after his Resurrection. In this meeting, Jesus does not condemn his disciples because most of them ran away from him when he suffered and died; instead, he comforts them by saying twice: “Peace be with you.” In this moment, he institutes the Sacrament of Penance, he breathes on his disciples, saying: “Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained.”
The Risen Christ gives the Holy Spirit and the gift of forgiveness to his disciples so that they can pass on to the world the forgiveness of sins, a gift that only God can give because it was paid for with the Blood of Jesus, the Son of God. “Peace” brings forgiveness to them and through them, others experience God’s forgiveness.
This Divine Mercy Sunday is a time for us to reflect on God's merciful love and his forgiveness. We should know that God always forgives and no longer remembers our sins (see Hebrews 8:12) if we are heartily sorry and detest all our sins. Therefore, the Sacrament of Penance is “usually followed by peace and serenity of conscience with strong spiritual consolation”(CCC 1469).