From the above source...
What is Speaking in Tongues and why does God say in 1 Corinthians 14:5 that He would like each Christian to do it?
No doubt that is a question that has been asked by millions of Christians through the centuries, and we believe that knowing the answer is vital for maximizing the quality of one's life as a follower of the Lord Jesus Christ. Why? The primary reason, as a study of Scripture will clearly show, is: speaking in tongues is the only absolute proof a Christian has that he is born again and guaranteed a parking place in Paradise, i.e., everlasting life (2 Cor. 1:21, 22; Eph. 1:13, 14; 1 John 3:24). Speaking in tongues is the only valid external, tangible evidence in the senses realm that the internal, intangible gift of holy spirit was shed abroad in one's heart at the moment of his new birth.
