Many Christian denominations believe that speaking in unknown tongues, or glossolalia, is an essential evidence of the baptism in the Holy Spirit. They find the origins of this phenomenon in the practice of the Chief Apostolic Church, reflected in the book of the Acts of the Apostles and in the 1st Epistle of the Apostle Paul to the Corinthians. Does the gift of tongues described by biblical authors correspond to modern glossolalia? Doctor of Theology Gerhard Hasel, known to many Protestant denominations for his studies of the Old Testament, conducts a theological analysis of those passages in the Bible that talk about speaking in tongues, and proves the complete inconsistency of the modern view of this gift of the One Who has been removed Spirit.