-- Acts 2:14, 22-33
Everything that happened during those Paschal days involves each of the apostles - and Peter in particular - in the building of the new era begun on Easter morning. As witnesses of the Risen One, they remain the foundation stones of his Church. The faith of the first community of believers is based on the witness of concrete men known to the Christians and for the most part still living among them. Peter and the Twelve are the primary "witnesses to his Resurrection", but they are not the only ones - Paul speaks clearly of more than five hundred persons to whom Jesus appeared on a single occasion and also of James and of all the apostles.
-- CCC 642
In the office of the apostles there is one aspect that cannot be transmitted: to be the chosen witnesses of the Lord's Resurrection and so the foundation stones of the Church. But their office also has a permanent aspect. Christ promised to remain with them always. The divine mission entrusted by Jesus to them "will continue to the end of time, since the Gospel they handed on is the lasting source of all life for the Church. Therefore, . . . the apostles took care to appoint successors."
-- CCC 860
"Do not be afraid.
Go tell my brothers to go to Galilee,
and there they will see me."
-- Mt 28:8-15
Even when faced with the reality of the risen Jesus the disciples are still doubtful, so impossible did the thing seem: they thought they were seeing a ghost. "In their joy they were still disbelieving and still wondering." Thomas will also experience the test of doubt and St. Matthew relates that during the risen Lord's last appearance in Galilee "some doubted." Therefore the hypothesis that the Resurrection was produced by the apostles' faith (or credulity) will not hold up. On the contrary their faith in the Resurrection was born, under the action of divine grace, from their direct experience of the reality of the risen Jesus.
-- CCC 644
(Art: Christ's appearance when the Apostles are at table, Duccio di Buoninsegna, 1308-11, tempera on wood, Museo dell'Opera del Duomo, Siena.)