After the Ascension of the Lord, the Apostles, together with Mary and some disciples, were waiting for the Holy Spirit, whose arrival had been announced by the resurrected Jesus. In those days of prayer and expectation, Peter invited the community to decide who should replace Judas Iscariot:
“It is necessary that one of those who have been in our company during all the time that the Lord Jesus remained with us, from the baptism of John until the day of the ascension, be constituted together with us as a witness of his resurrection” (Acts 1 , 21-22).
Immediately afterwards, Lucas points out: “Two names were proposed: Joseph, called Barsabás, nicknamed ‘the just’, and Matthias. And they prayed like this: ‘Lord, you who know the hearts of all, show us which of the two you chose to carry out the ministry of the apostleship, left by Judas when he went to his rightful place.’ They cast lots, and the choice fell on Matthias, who was added to the eleven Apostles” (Acts 1, 23-26).