This is a deep and foundational part of
Pentecostalism. It's a fascinating offshoot of Protestantism. I attended an Apostolic (one of many Pentecostal denominations) revival service one time with probably 100 people in it. They are big on laying of hands and speaking in tongues. In short, they see speaking in tongues as a sign that the Holy Spirit has personally touched someone and they are of pure heart and faith. Supposed to be an angelic language or something like that, and there are elders within the church that are supposed to translate the gibberish for the rest of the people. Personally I call BS, but whatever floats your boat. Among this branch of Christianity also lie the equally fascinating snake handling folks.