How do we know the doctrine of tongues is true?

The truth of the doctrine of tongues is substantiated by biblical accounts, such as those found in Acts 2 where the apostles speak in languages understood by people from various nations, enabling the proclamation of the gospel. Additionally, in 1 Corinthians 14, Paul instructs the church on the proper use of this gift, clarifying that it should be exercised in a way that edifies the church rather than serves as personal edification without understanding. This biblically grounded doctrine emphasizes that tongues should serve to communicate the gospel effectively.