The events of Pentecost day were among the most spectacular with the most far-reaching effects of any day in human history.
Jesus' resurrection from the dead, as crucial as it was, was witnessed by no one. We verify that the resurrection took place by its effects – the empty tomb, the post-resurrection appearances and the fearless adherence to the fact of the resurrection by the disciples in the face of enormous persecution.
On Pentecost, in contrast, a small number of people were present at the rush of a violent wind and saw tongues of fire come down upon them. They immediately began speaking in foreign languages that they previously did not understand and 3,000 people were added to the number of disciples on one day.
Peter, previously so fearful, immediately began proclaiming the good news to large numbers of people.
The primitive Church immediately began to assume its main characteristics – "the breaking of the bread," healings and prophecies, witness to the resurrection and other basic teachings, and the selfless sharing of goods among believers. Christian Baptism, it appears, did not take place before Pentecost but became commonplace after it.
The number of followers of the Way continued to grow rapidly, not only for months, but for centuries until Christianity, without any coercion, had become the dominant religion of the Roman Empire.
Clearly something of profound importance had taken place at Pentecost.
Pentecost had become or was becoming at that time a Jewish memorial of the handing down of the Mosaic Law on Mount Sinai. But now, because of the outpouring of the Spirit, there was a new law. It was a law, St. Paul would write, that was "written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts" (2 Corinthians 3.3).
In his writings, St. Paul would emphasize the personal sanctification of believers by the indwelling Spirit. St. Luke, however, had a different emphasis – the effective mission of the spread of the Gospel.
In Luke's presentation, Pentecost was the beginning of the end of the dispersal and misunderstanding among the peoples of the earth that began with the pride-filled erection of the Tower of Babel (Genesis 11.1-9). On Pentecost, the Good News was preached to Jews who had come to Jerusalem "from every nation under heaven."
The Baptism by fire and the Spirit that John the Baptist had regretted not seeing after Jesus' baptism in the Jordan was finally upon us. The fire that Jesus had wanted so earnestly to bring to earth was now kindled. Indeed, it was more than kindled. It was a raging inferno.
There were to be more Pentecosts that would lead to the net being cast much more widely than it was that day in Jerusalem. When Philip preached in Samaria and baptized many of the inhabitants, Peter and John went and prayed and laid hands on the new converts and they received the Holy Spirit (Acts 8.4-25).
Then Peter brought the Gospel to the centurion Cornelius and other Gentiles at Caesarea. While Peter was preaching, "the Holy Spirit fell upon all who heard the word." The circumcised believers with Peter were astounded.
This little Pentecost led the discerning Christian community to realize that the Holy Spirit was meant for Gentiles and Jews alike (Acts 10.1-11, 18). Out of this realization came the historic decision to send Paul and Barnabas to preach the Gospel to the Greeks.
Each of these little Pentecosts led to at least some of the new Christians receiving the gifts of tongues and prophecy. Moreover, through the Acts of the Apostles we gain the sense that the Spirit is not a nameless force, but a person who acts to facilitate the rapid spread of the Gospel. The Holy Spirit points not to himself but to Jesus.
Luke continues his account of the spread of the Gospel until finally Paul preaches in Rome, the centre of the known world. Pentecost, of course, does not end there; it continues into our day. But with the preaching of the Gospel in Rome, the die is cast – the Holy Spirit is destined for all people in all times.