Speaking in tongues” is found in the Speaking in tongues andrew bovell pdf in Mark 16, Acts 2, 8, 10, 19 and other new testament books. Especially it is explained in 1st Corinthians 12-14.
It is described, among other things, as “speaking directly to God”, “speaking mysteries”, “self edifying” and in Jude for “building ones faith”. Speaking in tongues is known as “perfect prayer”, heavenly language, prayer language, among other descriptions. Jesus were “filled with the Holy Spirit”, “baptized in the Holy Spirit and fire”, and “endued with power from on high”, among other descriptions. Charismatic, full gospel, Pentecostal, apostolic and non-denominational and other “Spirit-filled churches.