“For he who speaks in a tongue does not speak to men but to God, for no one understands him; however, in the spirit he speaks mysteries.” I Corinthians‬ ‭14:2‬ ‭NKJV‬‬

“A person who speaks in tongues is strengthened personally,…” 1 Corinthians‬ ‭14:4‬ ‭NLT‬‬

For if you pray in tongues, your spirit is praying, but you don’t understand what you are saying. (See 1 Corinthians‬ ‭14:14‬)

That is why all the disciples of Jesus Christ were speaking in tongues and all those they laid their hands on and prayed for. (See Acts 2:4 + Acts 19:5-7)