language barrier

When the day of Pentecost arrived, they were all together in one place. And suddenly there came from heaven a sound like a mighty rushing wind, and it filled the entire house where they were sitting. And divided tongues as of fire appeared to them and rested on each one of them. And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit gave them utterance. (Acts 2:1-4, ESV)

"we hear them telling in our own tongues the mighty works of God" v11b

The first activity of the holy spirit in the church is to allow them to talk in languages that they do not understand. This wasn't a freak show to attract attention (although it did attract attention), it was to cut across language barriers to share the news of the gospel. The point isn't the gift of tongues in itself, it is what they were saying. No matter what language you spoke on that day, you heard about "the mighty works of God". The tongues were the means by which the gospel was going out, not the focus in themselves.