Speaking in tongues (glossolalia)
Praying or speaking in a language not previously learned by the speaker.
Speaking in tongues, called glossolalia in technical theological usage, is the practice of praying or speaking in a language not previously learned by the speaker, understood as a gift of the Holy Spirit. In classical Pentecostal teaching (Assemblies of God Statement of Fundamental Truths, Article 8), speaking in tongues is the initial physical evidence of the baptism in the Holy Spirit; in Pentecostal practice it may also be a gift used in personal prayer and (with interpretation) in corporate worship. The biblical foundation is Acts 2, where the disciples speak in tongues at Pentecost, and 1 Corinthians 12 and 14, where Paul addresses the gift in the Corinthian church. Practice and emphasis vary across Pentecostal and Charismatic Christian traditions.