Even though the apostles spoke of God’s wonders, the speaking of different languages was not primarily a means to facilitate communication and to reach people of other languages with their message. As Peter will confirm in his speech (Acts 2:14–21), the speaking of different languages is a miraculous demonstration of the presence of God’s Spirit1 in fulfillment of God’s promises (see Numbers 11:29; Isaiah 32:15; Isaiah 44:3; Ezekiel 36:27; Joel 2:28–32).
11 both Jews and proselytes, Cretans and Arabians we hear them telling in our own tongues the mighty works of God.”