Long before it became a Christian feast, Pentecost had been a Jewish feast. Attending to that fact helps us understand Luke's narrative of what has rightly been called “the birth of the Church.” Pentecostes (Greek for “fiftieth”) is the Greek name for the Jewish feast of Weeks— so-called because it occurs seven weeks, or on the fiftieth day, after Unleavened Bread/Passover. These were the first two of the three classic pilgrim feasts of the Israelite religion. Originally agricultural feasts, Unleavened Bread celebrated the beginning of the cereal harvest. Weeks the end of the grain harvest, and Booths the vintage. Eventually each of these agricultural feasts became a commemoration of a specific event of Israel's sacred history. Unleavened Bread, joined early with Passover, became the time to recall the redemption from Egypt. Once that Passover/Exodus link was forged, it was almost inevitable that Weeks should be associated with the event that Exodus 19:1 places “in the third month after their departure,” that is, the giving of the Law on Mount Sinai, a meaning many scholars think the feast already had in Jesus' day.
These three pilgrim feasts were the occasions when Jews living in other parts of the Mediterranean world would prefer to visit the homeland. Indeed, the economy of Jerusalem depended on the income brought in by these pilgrim-tourists. One estimate is that the population of the city, around 140,000, doubled during these feasts, filling the inns and inundating the streets.
With those elements of the Jewish background of the feast in mind, watch how Luke tells of the Christian events on Pentecost in images that allude to those elements, showing how “the time for Pentecost” was indeed “fulfilled.” The reconstituted Twelve (with the 120) are gathered like the twelve tribes at Sinai. The sound from heaven, the filling of the entire house (like the shaking of the entire mountain in Exodus 19:18) and the fire recall the theophany at Sinai. The tongues of fire symbolize the powerful presence of God (like fire) that will find expression in human words, the prophetic ministry of the disciples (tongues). In the larger sweep of the narrative, the Moses connection is evident in that Jesus ascends with a cloud (1:9) and then mediates the gift of the word of God for his people (2:4, 11, 18, 33). Thus on the feast of the giving of the Law (the privileged communication of God's word) and the forging of the first covenant, the end-time gift of the Holy Spirit comes to bestow the blessings of the new covenant and to enable the new expression of the divine word in the ministry of the apostles.
Now it becomes clear why Luke lists the geographical origins of the Jewish pilgrims. By highlighting this inclusive gathering, Luke proclaims that this assembly is in fact the long-awaited end-time ingathering of Israel. The Pentecostal gift is destined for Jews first, but then for “the ends of the earth” (Acts 1:8), “those far off” (Acts 2:39; Is 57:19).
Some hear in Luke's account a reversal of the story of the tower of Babel. Whereas Genesis 11 tells of a sinful people who wish to make a great name for themselves and are scattered in confusion, losing their ability to communicate. Acts 2 tells of a people of many languages, gathered and “confused” (Luke says deliberately) by a new ability to receive communication, and enabled to become a new community as they repent from their sin and call upon the name of the Lord.
The rest of the Acts of the Apostles indicates that empowerment by the Holy Spirit is not simply some kind of “jump start” to get the Church going but the normal way the community expands through its mission outreach. And the reading from Paul's letter to the Christians in Corinth confirms that a local church is empowered by the Holy Spirit with a diversity of gifts, services, and works (Second Reading). It is to illustrate this empowerment that Paul develops his teaching on Church as body of Christ. The gifts, in all their diversity, are meant not for competition or self-aggrandizement but to build up that body in love. We read Luke, Paul, and John because we live in the same Church that is pictured in their writings.