In the Greek, the word translated as tongues is γλῶσσα, glōssa, meaning the literal tongue or a language.
When the gift of tongues (speaking in foreign languages) was first given at Pentecost, we know these languages were definitely understood by foreigners. Act 2:7-8, 11 (NIV), “Utterly amazed, they asked: ‘Aren’t all these who are speaking Galileans? Then how is it that each of us hears them in our native language?…(both Jews and converts to Judaism); Cretans and Arabs–we hear them declaring the wonders of God in our own tongues!’ ”
In verses 14-41 of Acts 2, Peter then teaches about the repentance of sins and the fulfillment of prophecy. The result was that 3,000 people were converted and baptized as a result of hearing the message in their own language. From this account, we can clearly see that the purpose of speaking in tongues was to preach and spread the gospel.
1 Corinthians 14:22 further explains, “Speaking in other tongues, then, is intended as a sign, not for believers but for unbelievers, while prophecy is not for unbelievers but for believers.” Speaking in tongues, foreign languages, gave the early church the ability to spread the Gospel far and wide.
In the time of Jesus, the New Testament had not yet been written. The Jews had the Old Testament scriptures, but even so, they needed instruction to understand the prophecies pointing to Jesus. People depended on the signs, miracles, and the gifts of the Holy Spirit to prove that Jesus was indeed God’s son.
However, the New Testament was written so that even 2,000 years after Jesus’s first advent, we can still learn and believe in God’s plan of salvation. The New Testament produces the exact same outcome as seeing signs and speaking in tongues. Today, we no longer need to depend on signs and wonders. Thus, the gift of speaking in tongues, along with the other miraculous signs, ended with the apostles.
To conclude, the purpose of speaking in tongues was to be a sign to the unbelievers and to spread the Gospel. Speaking in tongues is no longer happening today. It has not been in place since the days of the apostles before the New Testament was completed.
For a more detailed study of tongues, please download the free PDF: "Speaking in Tongues"