Gospel (Jn 20,19-31) - On the evening of that day, the first of the week, while the doors of the place where the disciples were were closed for fear of the Jews, Jesus came, stood among them and said to them: "Peace be with you!". Having said this, he showed them his hands and his side. And the disciples rejoiced when they saw the Lord. Jesus said to them again: «Peace be with you! As the Father sent me, I also send you." Having said this, he breathed and said to them: «Receive the Holy Spirit. Those whose sins you forgive, they will be forgiven; those whom you do not forgive, they will not be forgiven." Thomas, one of the Twelve, called Didymus, was not with them when Jesus came. The other disciples said to him: "We have seen the Lord!". But he said to them, “Unless I see the mark of the nails in his hands, and put my finger into the mark of the nails, and put my hand into his side, I will not believe.” Eight days later the disciples were back in the house and Thomas was also with them. Jesus came, with the doors closed, stood in the middle and said: «Peace be with you!». Then he said to Thomas: «Put your finger here and look at my hands; stretch out your hand and put it in my side; and do not be an unbeliever, but a believer! Thomas answered him: «My Lord and my God!». Jesus said to him: «Because you saw me, you believed; Blessed are those who have not seen and have believed! Jesus, in the presence of his disciples, did many other signs that are not written in this book. But these were written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name.

The commentary on the Gospel by Monsignor Vincenzo Paglia

This second Sunday of Easter is dedicated to the mercy of God. It was established by John Paul II who accepted an indication from the Polish nun Faustina Kowalska, a woman who spread devotion to the mercy of God since 1931 and in the following years. They were terrible times for Europe and this nun understood the need for mercy. And she insisted that the Sunday after Easter be dedicated to mercy. She said: in the death and resurrection of the Lord, God's mercy had reached its culmination, its fulfillment. The Gospel passage helps to understand the meaning of mercy even more.
The evangelist John takes us back to the evening of Easter and the evening of eight days later, as if to mark the time of the Church, from Sunday to Sunday. In fact, from that day until today - many centuries have passed - the memory of Easter has always been celebrated in the Church every Sunday. It is not the memory of a bygone past. Every Sunday the Risen One returns to his disciples and places himself among them. They struggled to recognize it, as we too often struggle, caught up as we are in ourselves, in our thoughts, in our insensitivities. The risen Jesus shows the wounds of his body. This is the sign that opens the eyes of the disciples. The risen Jesus is marked by wounds. As if to represent the many crucifixes of the earth still today. The risen Jesus preserves his wounds. And he continues to get emotional about them. He, the merciful one, allows himself to be hurt by the cry of the poor. There is no resurrection without taking on one's body the wounds of men. So it is for the Church: a community of disciples sent by the Risen One to forgive, to heal, to disarm hearts from violence.
It is the path of mercy that the Lord continues to follow without stopping. Eight days later, the Lord returns, comes among us and also speaks to that part of Thomas that is present in the heart of each of us. He begins by repeating the greeting of peace: "Peace be with you." And he immediately turns to Tommaso, inviting him to touch his wounds with his hands. And he adds: «Do not be an unbeliever, but a believer!». And Thomas professes his faith: "My Lord and my God". The "looking" indicates an intense gaze that captures the mystery of that "pierced" body.
Here Jesus proclaims the last beatitude of the Gospel, the one that is the foundation of the generations that from that moment until today will join the group of the Eleven. What does the bliss of faith without seeing mean? The episode of Thomas suggests that faith, from that moment on, does not arise from the vision of Jesus as the apostles had, but from listening to the Gospel of the apostles "we have seen the Lord!" and from touching the wounds of the resurrected body of Jesus.