The following comes from the CNA:
The Holy Father welcomed Divine Mercy Sunday from the Apostolic Palace of Castel Gandolfo, focusing his address before the Marian prayer on Sunday's reading from the Gospel of John. In his words, he acknowledged the value of Thomas' doubt for Christians today and reflected on Jesus' imparting of the Holy Spirit and the mission of the Church.
St. John's account which narrates Jesus' visit to the disciples in the Cenacle after his resurrection, said the Pope, is "rich" with "mercy and divine goodness."
Benedict XVI quoted St. Augustine who explained the scene in which Christ's body, "inhabited by divinity," is not impeded from entering the closed doors of the Upper Room. St. Gregory the Great, he noted, described the Redeemer's arrival in a state of glory, with an uncorruptible and palpable body.
Once in the room, Jesus allows the "incredulous" Thomas to verify the signs of the passion present on Jesus' body, recalled the Pope, adding that the "divine compliance" of Jesus in permitting Thomas to touch him continues to be as profitable for us as it was for the other disciples.
"In fact, touching the wounds of the Lord, the doubtful disciple cures not only his, but also our diffidence," he observed.
Putting the scene in perspective, the Holy Father explained that the Risen Christ's visit was not limited to the Cenacle, "but goes beyond, so that everyone may receive the gift of peace and life with the 'Creating Breath.'"
In Jesus' words and actions in the locked upper chamber, he establishes the mission of the Church ever aided by the Holy Spirit, which is, the Pope said, "to carry out to all the glad announcement, the joyous reality of the merciful Love of God ..."
Pope Benedict concluded his words by encouraging priests, "in light of this word," to follow the example of St. Jean Vianney in helping people to "perceive the merciful love of the Lord" whose announcement and a "witness to the truth of Love" is important also today.
"In this way we will make ever more familiar and close He that our eyes haven't seen, but of his infinite Mercy we have absolute certainty."
Beginning the Regina Caeli prayer, he asked for the intercession of the Virgin Mary, Queen of the Apostles, in "sustaining the mission of the Church."
In his post-prayer address, he remembered those from Poland who died in a tragic plane crash on Saturday morning in Russia. He also welcomed the opening of the exposition of the Shroud of Turin and wished a blessed Divine Mercy Sunday to all.