Pentecost

Pentecost is the descent of the Holy Spirit upon the apostles fifty days after Pascha — the "birthday of the Church," when the frightened disciples were clothed with power and began to preach Christ to all nations.

For Inquirers

For fifty days after the Resurrection, the disciples had a risen Christ but not yet the boldness to say so in public. They had seen the empty tomb, eaten with Him, watched Him ascend — and they were still, by their own account, mostly hiding indoors. Then, on a single ordinary morning, that changed all at once. A sound like a violent wind filled the house where they were gathered; something like tongues of fire appeared and rested on each of them; and men who had been too afraid to admit knowing Jesus a few weeks earlier walked outside and began preaching Him to crowds of strangers, in languages they had never learned.

This is why Christians call Pentecost the birthday of the Church. Everything before this moment — the teaching, the miracles, even the Resurrection itself — had happened, in a sense, to a small, frightened group of followers. Pentecost is when that group becomes something else: a body of people given the power to carry what they had witnessed to the whole world, starting immediately, in front of visitors "from every nation under the sky."

Overview

Fifty days after Pascha and ten after the Ascension, the Holy Spirit descended on the gathered apostles with a sound of rushing wind and tongues "as of fire" (Acts 2.1-4).
Filled with the Spirit, they began to speak in other languages, and Jews gathered in Jerusalem "from every nation under the sky" heard the wonders of God each in his own tongue (Acts 2.5-11) — a reversal of the ancient confusion of tongues at Babel (Genesis 11.1-9).
St. Peter preached to the crowd, declaring the event the fulfillment of the prophet Joel's promise that God would "pour out my Spirit on all flesh" (Acts 2.16-18), and about three thousand were baptized — which is why Pentecost is called the birthday of the Church.
Pentecost completes the arc that runs from the Passion through the Resurrection and Ascension: Christ's own promise that His going would make the Spirit's coming possible (John 16.7) is fulfilled here.

The sound and the fire

Luke's account is spare and physical: "when the day of Pentecost had come, they were all with one accord in one place. Suddenly there came from the sky a sound like the rushing of a mighty wind, and it filled all the house where they were sitting. Tongues like fire appeared and were distributed to them, and one sat on each of them. They were all filled with the Holy Spirit and began to speak with other languages, as the Spirit gave them the ability to speak" (Acts 2.1-4). Nothing here is metaphorical or merely inward; the Spirit's arrival is given sound, sight, and immediate, visible effect.

What follows widens the scene from a single room to the whole known world. Luke names the crowd with deliberate specificity — "Parthians, Medes, Elamites, and people from Mesopotamia, Judea, Cappadocia, Pontus, Asia, Phrygia, Pamphylia, Egypt… Cretans and Arabians" (Acts 2.9-11), Jews gathered in Jerusalem from every direction of the known world — and each one hears the apostles "speaking in our languages the mighty works of God" (Acts 2.11).

Undoing Babel

The Church has always read this scene against the background of an older one. At Babel, humanity, united in language and in a single act of pride, is deliberately scattered: "the Lord said… let us there confound their tongue, that they may not understand each the voice of his neighbour. And the Lord scattered them thence over the face of all the earth" (Genesis 11.6-8). St. Gregory the Theologian, preaching on this very feast, draws the contrast explicitly: at Babel "the unity of their intention was broken up, and their undertaking destroyed," but at Pentecost, "much more worthy of praise is the present miraculous one. For being poured from One Spirit upon many men, it brings them again into harmony."[^greg-babel] Babel scattered a humanity that was united only in wickedness; Pentecost gathers a humanity still divided by language into a single hearing of one gospel. The confusion of tongues is not undone by force, and no single language is imposed — everyone hears "in his own language" (Acts 2.6) — but the division itself no longer prevents understanding.

The Church's first sermon

Peter, the same man who denied Christ three times a few weeks earlier, stands and explains what the crowd is seeing not as drunkenness but as prophecy fulfilled: "this is what has been spoken through the prophet Joel: 'It will be in the last days, says God, that I will pour out my Spirit on all flesh. Your sons and your daughters will prophesy…'" (Acts 2.16-18). The sermon that follows proclaims the crucified and risen Christ directly to the crowd that had, weeks before, called for His death; Luke records that "about three thousand souls" were added that day. This is why the Church keeps Pentecost as one of the Great Feasts and as the effective birthday of her public life: the community that had witnessed the Resurrection in private now begins, on this day, to proclaim it in public, to strangers, in their own languages.

Gregory the Theologian, reflecting on the whole arc from Christ's earthly life to this moment, traces the Spirit's activity through three stages — "before Christ was glorified by the Passion, and after He was glorified by the Resurrection; and after His Ascension… to Heaven" — culminating in "the present distribution of the fiery tongues, which we are now commemorating," in which the Spirit is present "no longer only in energy, but… substantially, associating with us, and dwelling in us."[^greg-stages] Pentecost is therefore not a separate event bolted onto the end of the Gospel story but its intended completion: the Passion, the Resurrection, and the Ascension all lead here, to the Spirit permanently indwelling the Church Christ founded.

Sources

[^1]: Acts 2.1-4 (WEB) — the descent of the Spirit with wind and tongues of fire at Pentecost. [^2]: Acts 2.5-11 (WEB) — the nations gathered in Jerusalem, each hearing the apostles in his own language. [^3]: Genesis 11.1-9 (Brenton LXX) — the confusion of tongues at Babel, the scene Pentecost is read against. [^4]: Acts 2.14-41 (WEB) — Peter's sermon, the citation of Joel's prophecy, and the baptism of about three thousand. [^greg-babel]: St. Gregory the Theologian, Oration 41 ("On Pentecost"), §16 — Babel's confusion contrasted with Pentecost: "much more worthy of praise is the present miraculous one. For being poured from One Spirit upon many men, it brings them again into harmony.". [^greg-stages]: St. Gregory the Theologian, Oration 41, §11 — the Spirit's activity "before Christ was glorified by the Passion, and after He was glorified by the Resurrection; and after His Ascension… to Heaven," culminating in the tongues of fire, present now "substantially, associating with us, and dwelling in us.".