While he was on earth, Jesus was directly present with his followers, who, even with their obvious shortcomings, did provide evidence of believing in him to whatever extent was possible (“Lord, to whom shall we go? You have the words of eternal life.” “You are the Christ.” “I believe; help my unbelief.”). There is no clean and easy way to determine the exact point in which the disciples became believers in the sense we use the term.  

They did “believe” when Jesus was alive, but their faith was not complete until the resurrection, just as Christ’s work of redemption was not complete. The disciples were sanctified by the word of Jesus while he was with them (John 13:10; 15:3; 17:17), but they would not receive the Spirit as the power of the risen Christ until after the resurrection (as promised in John 14–17). By historical and experiential necessity, the disciples occupy a different place in salvation history than we do. 

In Acts 2:33 Peter says that Jesus “received” the Spirit from the Father specifically for the pouring out received at Pentecost. On the other hand, at Acts 8:17 some Samaritans receive the Spirit when Peter and John lay hands on them. 

In Acts 10:47, Peter declares that because Cornelius and other Gentiles “received” the Spirit just as Jewish believers did, there is no way to deny them baptism. The Spirit “fell” upon all gathered as Peter spoke, and those with Peter were amazed that the Spirit was “poured out” on the Gentiles just as he was on Jewish believers (Acts 10:44–45). Thus it is clear that the language for receiving the Spirit, whether for particular empowerment or for regenerating power, does not consistently distinguish between the work of witness and that of belief. All of these works—apostolic witness, signs and wonders, and regeneration—are entirely the doing of the Spirit. How the Spirit is working and what he is bringing about depends on the context. 

Outward manifestation

The Spirit came and “rested on each one” at Pentecost (Acts 2:3). This is an outward manifestation of what is taking place among them, as all those gathered in the room are “filled with the Holy Spirit” (Acts 2:4) — what Jesus promised them at his ascension now takes place. It is impossible to quantify what it means to be “filled with the Holy Spirit.” We should not think of the Spirit as some sort of heavenly gasoline that fills our spiritual tank. 

 Luke seems to be speaking in the sense of capacity (“filling” language), but how do we think of capacity when the receptacles are people and the substance is the Holy Spirit? Can someone be filled a quarter of the way with the Spirit? At what point is one “full” of the Spirit in terms of quantity? Paul tells the Ephesian believers, who already have the Spirit, nevertheless to “be filled with the Spirit” rather than to be drunk on wine (Eph. 5:18).

In his Gospel, Luke uses the word “filled” in the sense of filling to capacity, as when the disciples’ boats are so full of fish that they begin to sink (Luke 5:7), or figuratively, as in “filled with great fear” (Luke 2:9) or “filled with fury” (Luke 6:11). He also uses the term to mean “fulfill” or “end,” as in to reach an appointed conclusion. Zechariah goes back home “when his time of service [as a priest] was ended” (Luke 1:23). The destruction of Jerusalem foretold in the Olivet Discourse is described as “days of vengeance, to fulfill all that is written” (Luke 21:22). 

Importantly, the angel tells Zechariah that his son, John, “will be filled with the Holy Spirit” (Luke 1:15); Elizabeth sees Mary and is “filled with the Holy Spirit” and begins to praise (Luke 1:41); and Zechariah is, once again, “filled with the Holy Spirit” and begins to prophesy and to praise God for what he is about to do in Israel according to his promises (Luke 1:67).

We find similar texts in Acts as well. Peter is filled by the Spirit and speaks to a crowd (Acts 4:8), and soon after the believers are filled with the Spirit through prayer (Acts 4:31). When the seven are chosen to look after the widows among the Greek-speaking Jews, one of their criteria is that they are to be filled with the Spirit (Acts 6:3). Ananias tells Paul he will “be filled with the Holy Spirit” (Acts 9:17). 

These texts, along with those in Luke, determine what the phrase means in Acts 2:4 and in Acts generally. In most cases, to be “filled with the Holy Spirit” means to be empowered for service, usually that of proclamation or mission. This does not imply an initial lack but merely communicates a special experience of the Spirit in order to carry out the mission from Jerusalem and Judea to Samaria and the ends of the earth. The Spirit’s work in salvation does not take second place in Acts—reception of the Spirit is the primary reason Gentiles must be baptized and recognized as full-fledged members of the new covenant (Acts 15:8–9)—but at Pentecost specifically the disciples are filled with power for the great work of that day.

Throughout Acts, the Spirit works in believers to empower them for service.

The meaning of tongues 

As a result, those in the room “began to speak in other tongues as the Spirit gave them utterance” (Acts 2:4; cf. Acts 10:45–46; 19:6). The meaning of the word translated “tongues” (Gk. glōssai) is disputed. Many Christians understand this verse to mean that the disciples begin to speak in a heavenly language transcending human linguistic structures — unlike any language on earth. In such an interpretation, those who hear the disciples speaking in different languages (Acts 2:6) do so because some kind of divine translation is taking place that causes the “tongues” to be heard as languages.  

Often in this interpretation the miracle of tongues is accompanied by a miracle of hearing. Texts such as 1 Corinthians 13:1, where Paul mentions speaking in the “tongues of men and of angels,” are cited in support (cf. 1 Cor. 14:2, 18–23, 27). Others, however, understand the disciples to be speaking in different languages, those represented in the room that day. In this interpretation there is no need for a miracle of hearing. Typically, this reading is accompanied by reading the term “tongues” in the NT as always referring to known human languages. 

First Corinthians 13:1 does, however, seem to distinguish human and heavenly speech. Pressing glōssaito mean “languages” in every instance in the NT seems strained. A third option is to understand the word “tongues” as being used in the NT both for human languages and for heavenly speech, with both manifestations being works of the Spirit.

At Pentecost the tongues seem to be languages, and thus the miracle is one of speaking, not likely one of hearing. Luke here uses the word apophthengomai (“utterance”; Acts 2:4), which recurs twice more in Acts in regard to speaking God’s word. It is clear that the Spirit empowers the disciples’ speaking, but, as seen in the upcoming verses, there is no similar indication of Spirit-empowered hearing. 

Throughout Acts, the Spirit works in believers to empower them for service. The Spirit does work in unbelievers, but this is part of God’s work of salvation, “having cleansed their hearts by faith” (Acts 15:9). Such is why it is important first to establish what “filled” means in this verse before considering the miracle of speaking that follows: it provides the context for understanding this highly disputed text.

Editors’ note: This article is adapted from the ESV Expository Commentary: John–Acts (Volume 9). It was originally published on the Crossway blog.