1. The Church came to exist when Jesus Christ called the disciples and began to form them in the Good News of Salvation. But Pentecost is rightly considered the birthday of the Church. What was largely hidden from the eyes of the world now burst forth upon the scene, with rushing wind, tongues of flame, and powerful and effective preaching (Acts 2:1-11).
2. The word Pentecost comes from Greek, meaning 50 days. It was originally a word used by the Greek speaking Jews to indicate the end of the 50 days of harvest after the feast of Passover (see this in the Jewish Encyclopedia). Harvest would begin with the barley and end with the wheat, because wheat took longer to ripen. The feast would include a day of rest as well as the sacrifices of the first fruits of the harvest. It was believed that Moses deliberately arranged it to fall on Sunday, so that everyone would have two days of rest in a row (Saturday being their Sabbath). In some places it was customary to read the Book of Ruth, because the harvest figures into her story, but also because she became a convert to Judaism.
3. The Christian feast of Pentecost is the fulfillment of the ancient feast. Our Pentecost is celebrated always on a Sunday. It is 50 days after Easter, which is referred to during the Easter Vigil as our passover feast. Note in the Passover, the Lambs are sacrificed and their blood is sprinkled on the doorposts so that the sons of the Israelites would be saved from the angel of death. In the mystery of Jesus Christ, it is He the Son of God, the True Lamb, who is sacrificed so that all people may be saved from the power of death. In the Last Supper, we are invited to share mysteriously in this same sacrifice of Jesus on the Cross.
4. In the Jewish feast of Pentecost, the first fruits of the harvest are brought before the Lord in thanksgiving. At the feast of Pentecost, the first fruits of the harvest of souls is brought before the Lord by the preaching of the apostles. Remember the many parables of Jesus which compared the evangelization of the world to the sowing of the seed of truth and the harvest of believers brought to faith and baptism ( for example: Matthew 9:37-38, Matthew 13:24-30).
5. The gift of the Holy Spirit, which the disciples received on Pentecost empowered them to fulfill the mission given to them by the Redeemer Jesus Christ. In spite of being with Jesus for about three years and receiving His teaching and observing His many signs, the disciples were still missing something. They were afraid. They were still thinking in a worldly manner. Yet all that changed with the infusion of the Holy Spirit. Those who had hidden themselves out of fear for what people might think or say or do became fearless in their proclamations regarding the Risen Christ. Those who had longed for a worldly kingdom and worldly power now yearned for a heavenly kingdom. Those who may have been regarded as ignorant were now able to demonstrate through scripture and argument that Jesus is indeed the Lord, the Son of God. Furthermore, many of those who previously might have shouted Crucify Him! now listened intently and received the gift of faith. These converts could be said to be in some sense the “first fruits” of those who would come into the Body of Christ which is the Church. In any event, the disciples and those who were added to the Lord that day received Courage, Wisdom, Knowledge, Understanding, Right Judgement, Piety and Fear of the Lord- all the gifts of the Spirit.
6. The Church has also received one other gift through the Holy Spirit- that is the gift of indefectability. That is, the Holy Spirit guides and protects the Church from falling away from Jesus. It is true that individual Christians, whether they be lay people or even deacons, priests, or bishops can sin or make mistakes. But Jesus promised that Hell would not prevail against the Church (Matthew 16:18). And it is through the Holy Spirit that God keeps His promise to us.
7. Like the Disciples at Pentecost, we have received the gifts of the Holy Spirit. These gifts are given to us so that we may accomplish our part in the mission to bring Jesus Christ to every creature. But there is one thing to consider. If after the Spirit descended on the disciples they would have remained in the upper room, if they had failed to make an appearance in the Temple precincts to begin preaching the truth out loud and without fear, where would we be now? Likewise, we cannot be afraid. We need to stand up for the truth. We need to share with others our faith in Jesus Christ the Risen Savior. Come Holy Spirit!