What does Acts 2:4 mean?
Immediately before Jesus ascended into heaven, He told His followers to wait in Jerusalem for the arrival of the Holy Spirit (Acts 1:4–5). That time has come, and the Holy Spirit has entered the house where they're waiting and touched each one with what appears to be a tongue of fire (Acts 2:1–3).The Holy Spirit is giving the Jesus-followers the ability to speak in different languages about the "mighty works of God" (Acts 2:11). Jerusalem is filled with Jews from many different countries who have come for Pentecost, also known as the Festival of Weeks (Leviticus 23:15–21). Not all of them speak the same language. The purpose of the apostles is to spread the message that Jesus' sacrifice makes it possible for people to be forgiven of their sins and reconciled to God. To do this on this day, they need to be able to be understood by the people around them.
Two thousand years later, in a culture that analyzes theology—and sometimes over-analyzes theology—this verse brings up two points of debate: the difference between being indwelt by the Holy Spirit vs. being filled by the Holy Spirit and the nature of "speaking in tongues."
Until this very moment, the Holy Spirit did not indwell God-followers. He filled them as needed to complete unique missions as prepared for them by God. Some were inspired by the Spirit to accomplish great feats of art (Exodus 31:3; 35:31), some to prophesy (Micah 3:8). John the Baptist, the last of the Old Testament-era prophets, was filled with the Spirit from before his birth (Luke 1:15), which was how he recognized Jesus when both were still in the womb (Luke 1:41–44). The filling of the Holy Spirit was temporary and didn't necessarily happen only to perfectly-clean, committed believers: for example, King Saul was filled for a short time and even prophesied (1 Samuel 10:10–11).
After Jesus ascended to heaven, God sent the Holy Spirit to permanently indwell each believer. He seals us, identifying us as belonging to God (2 Corinthians 1:22; 5:5; Ephesians 1:13–14). And Jesus promises the Holy Spirit will never leave us (John 14:16). Those of us who are indwelt by the Holy Spirit can also experience the filling of the Holy Spirit, as people did in the Old Testament. The Holy Spirit filled Stephen so he could face his death (Acts 7:55–60). Paul was filled on occasion (Acts 9:17; 13:9) and told us that we should seek to be, as well (Ephesians 5:18). But whether we are filled with the Holy Spirit or not, Jesus-followers can rest in the fact that He does live in us.
The more controversial issue brought up in this verse is that of speaking in tongues. Some Christians believe tongues are a heavenly language by which we talk to God without knowing what we're saying. Others think it is a way God prophesies to others through us, although it will take someone to interpret for people to understand the words. This passage gives a clear indication, however, that "real" speaking in tongues means spontaneously talking in a foreign language so those who need to hear the message can understand what we're saying. It is not gibberish, is targeted at someone who understands that speech, and it's useless if there's no one there who can translate or understand that language.
Devout followers of Christ often differ in their understanding of "tongues." The issue is not essential for salvation or the forgiveness of sins. We are free to disagree and live in unity in God's universal church.
