Pentecost Sunday is one of the most ancient feasts of the Church, celebrated early enough to be mentioned in the Acts of the Apostles (20:16) and St. Paul’s First Letter to the Corinthians (16:8). It is the 50th day after Easter and it supplants the Jewish feast of Pentecost, which took place 50 days after the Passover and which celebrated the sealing of the Old Covenant on Mount Sinai.
The Acts of the Apostles recounts the story of the original Pentecost as well (Acts 2). Jews from all over were gathered in Jerusalem to celebrate the Jewish feast. On that Sunday, ten days after the Ascension of Our Lord, the Apostles and the Blessed Virgin Mary were gathered in the Upper Room, where they had seen Christ after his Resurrection. Christ had promised his Apostles that he would send his Holy Spirit, and, on Pentecost, they were granted the gifts of the Spirit. The Apostles began to preach the Gospel in all of the languages that the Jews who were gathered there spoke, and about 3,000 people were converted and baptized that day. That is why Pentecost is often called “the birthday of the Church.” On this day, with the descent of the Holy Spirit, Christ’s mission is completed, and the New Covenant is inaugurated. It’s interesting to note that St. Peter, the first pope, was already the leader and spokesman for the Apostles on Pentecost Sunday.
Almighty and ever-living God, you fulfilled the Easter promise by sending us your Holy Spirit. May that Spirit unite the races and nations on earth to proclaim your glory. Grant this through our Lord Jesus Christ, your Son, who lives and reigns with you and the Holy Spirit, one God forever and ever. Amen.