The first occurrence of the gift of speaking in tongues occurred on the day of Pentecost in Acts 2:1-4. The apostles went out and shared the gospel with the crowds, speaking to them in their own languages: “We hear them declaring the wonders of God in our own tongues!” (Acts 2:11). The Greek word translated tongues literally means “languages.” Therefore, the gift of tongues is speaking in a language the person speaking does not know in order to minister to someone who does speak that language.
Mark 16:17 – right before Jesus ascended into heaven, He prophesied “they will speak in new tongues.”
There are only four instances in the New Testament where people speak in tongues:
Acts 2:3 – when the Holy Spirit descended upon the twelve apostles on Pentecost Sunday, they began to speak in tongues. Acts 2:6 says that men from fifteen different nations each heard the apostles speaking in their own language.
Acts 10:44-46 – after Peter preached the gospel, the Holy Spirit fell upon all who heard the word, and they (including the Gentiles) began to speak in tongues.
Acts 19:5-6 – after Paul baptized and confirmed about twelve Ephesians, they spoke with tongues.
1 Cor. 12-14 – Paul teaches that members of the Corinthian church had the gift of speaking in tongues.
In each instance in the book of Acts, tongue speaking is heard as if it is a foreign language. This gift of the Holy Spirit was for the purpose of spreading the gospel to all peoples of the world. Peter supports this view when he equates the Gentile tongue-speaking with the tongue-speaking at Pentecost (which was heard as foreign languages) when he says “the Holy Spirit fell on them just as on us at the beginning” (Acts 11:15).
In 1 Corinthians chapters 12–14, Paul discusses miraculous gifts, saying, “Now, brothers, if I come to you and speak in tongues, what good will I be to you, unless I bring you some revelation or knowledge or prophecy or word of instruction?” (1 Corinthians 14:6). According to the apostle Paul, and in agreement with the tongues described in Acts, speaking in tongues is valuable to the one hearing God’s message in his or her own language, but it is useless to everyone else unless it is interpreted/translated.