The day of Pentecost (Acts 2) marks the shifting of God’s redemptive purpose from a particular people (the descendants of Abraham via Isaac and Jacob) to all peoples. On that day the Church was formed and empowered for its worldwide mission; the event thus marks the resumption of universal history, with which the Bible begins (Gen. 1–11). Accordingly, Pentecost has primary importance to all who are concerned with the nature and purpose of the Church, particularly its mandate to preach the gospel of the kingdom throughout the world as a witness to all nations; “and then the end will come” (Mt. 24:14).
Glasser , A. F., “Pentecost“ In ISBE, revised, ed. Geoffrey W. Bromiley, vol. 3, (WM. B. Eerdmans, 1988; 2002), 757.