These are more commonly known as ‘tongues.’ Here some of the biblical basics.
Questions and Answers about Spirit-Inspired Languages
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Tag Archives: Do tongues have to go with baptized in the Spirit?
Are ‘Tongues’ the Sign of Baptism with Spirit in Acts?
What do five key passages in Acts say about prayer languages, commonly called ‘tongues,’ being the sign of the empowerment of the Spirit?
Baptized, Filled, and Full of the Spirit: What Does It All Mean?
All the key words are here, spelled out in simple English.
Dr. Jim's Essential Bible Teaching 