The Scriptures only mention the miraculous gift of tongues-speaking in a handful of places — six, to be exact. But from these six passages, three in the book of Acts and three in the book of 1 Corinthians, it seems clear that tongues-speaking was a regular and important practice in the life of the early church.
In the first century, speaking in tongues often accompanied the initial giving of the Holy Spirit to a particular people group. We see this in Acts 2, where people from all over the world had come to Jerusalem to celebrate the Passover feast. This diverse and multilingual group was amazed when the apostles, all uneducated men from Galilee, began preaching the good news of Jesus. Instead of hearing the message in Aramaic (the common trade language of the day), each listener heard the gospel in their native language. The gift of tongues is also seen as confirmation that the Gentile (non-Jewish) believers in Caesarea and the disciples of John the baptizer in Ephesus had received the Holy Spirit.
In addition to these descriptive passages in Acts, we also know that the church in Corinth practiced speaking in tongues well into the last half of the first century.
The passages in Acts are descriptive. They tell us what happened. The passages in 1 Corinthians are prescriptive — telling us how the gift should be practiced.
Here are just a few of the instructions the apostle Paul gives to the church at Corinth about the gift of tongues and its use:
- The gift of tongues is one gift among many and not everyone will receive it.
- If the gift of tongues, or any other spiritual gift, is practiced apart from love it is worthless.
- It, along with the gifts of prophecy and knowledge, will eventually pass away.
- Possessing the gift of tongues should be a cause for humility, not pride.
- It should not be forbidden, but practiced in a way that draws the hearers toward Christ.
- There must be an interpreter present if the gift is used publicly; if not, then the speaker should remain quiet and speak to themselves and God.
- It must be practiced in an orderly and decent manner.
Many things are unclear regarding the spiritual gift of tongues, and there is a great deal of disagreement among Christians regarding it as a legitimate practice for our day. But what seems abundantly clear from the Scriptures is that when God gave this good gift on the day of Pentecost, he gave it for a good purpose—to expand the gospel. It demonstrated his power to restore what was confused at Babel and foreshadow the final restoration of all things.
After this I saw a vast crowd, too great to count, from every nation and tribe and people and language, standing in front of the throne and before the Lamb. They were clothed in white robes and held palm branches in their hands. And they were shouting with a great roar, “Salvation comes from our God who sits on the throne and from the Lamb!” (emphasis added)
 Acts 10:46
 Acts 19:1–6
 1 Corinthians 12:1–14:40
 1 Corinthians 12:10, 28 & 30
 1 Corinthians 13:1 & 8; 14:1
 1 Corinthians 13:8
 1 Corinthians 14:1–5
 1 Corinthians 14:6–25 & 39
 1 Corinthians 14:26–28
 1 Corinthians 14:40
 Genesis 11:1–9
 Revelation 7:9–10