The Jewish feast of Pentecost, observed on the fiftieth day after Passover, was instituted to mark the first harvest in the Promised Land. By the time of Jesus it had become associated with the establishment of the Old Covenant on Mount Sinai. There is symbolism in the passage from Acts. The mighty wind would bring to mind the power of the wind that separated the waters of the Sea so that Moses and the people could pass over the waters to escape the Egyptian army; the tongues of fire would bring to mind the pillar of fire, sign of God's presence in the desert, leading them on. It could also signify the words of the prophets proclaiming God's messages to the people. In the context of our christian Pentecost, the tongues of fire are sign of the Spirit's presence, enabling those present to understand God's new message of salvation. Luke borrows such imagery descriptive of the theophanies of God in times past.
For us Pentecost, the commemoration of the descent of the Holy Spirit, marks the epiphany of the Church. Traditionally we profess that the Church was born from the pierced side of Christ on the Cross. Today we commemorate the first public manifestation of the Church in the world, by the preaching of the apostles. One of the marvels on this occasion is that all present understood in his/her native tongue what was announced. The rift of Babel was healed. The disruption of order and confusion of Babel was now ended, or it became possible to end it, by the universal language of love, a gift of the Holy spirit.
We respond: "Bless the Lord, O my soul! ... My God, you are great indeed." This is the opening verse of Psalm 104. we go on to recognize the many works of the Lord (vs. 2), not the least of which is the renewal of "the face of the earth" by sending forth of his Spirit (vs. 30). For this we pray that "the glory of the Lord (will) endure forever" (vs. 31). The renewal of life and the endurance of the glory of the Lord is guaranteed by the presence of the Spirit among us. And so in the context of our christian Pentecost verses from Psalm 104 are an appropriate response to the graces of this celebration.
In Paul's time many people claimed to be inspired by the Holy Spirit. But Paul challenges the authenticity of many. Writing to the Corinthians, Paul teaches that all spiritual gifts are channeled through Jesus, and are for the good of all, not for personal aggrandizement.
[The passage from Romans recalls that the Spirit of God has taken up permanent residence within each christian; the Spirit elevates each of the baptized to the dignity of being a child of God.]
In John's gospel the Church is born from the pierced side of Christ,and given proof by Jesus' resurrection form the dead, and a commission to the disciples to go forth with the power of the Holy Spirit to continue the ministry of Jesus. The significance of breathing on the disciples is that now we have a new creation taking place, a breathing that signifies the installation of new life.