Speaking in an unknown language

Scripture references

1 Corinthians 12:10 (ASV 1901)

10and to another workings of miracles; and to another prophecy; and to another discernings of spirits: to another divers kinds of tongues; and to another the interpretation of tongues:

1 Corinthians 14:2–4 (ASV 1901)

2For he that speaketh in a tongue speaketh not unto men, but unto God; for no man understandeth; but in the spirit he speaketh mysteries. 3But he that prophesieth speaketh unto men edification, and exhortation, and consolation. 4He that speaketh in a tongue edifieth himself; but he that prophesieth edifieth the church.

Stories

Jackie Pullinger speaks in tongues after an encounter with other believers.
Ah Tong was desperate to get off drugs. When he asked Poon Siu Jeh for help, Poon introduced him to Jesus and to some men who had been in jail with Ah Tong but are now believers in Jesus. Ah Tong accepted Jesus after listening to their story, he received deliverance, peace, joy and smiled like never before.