"It is a mistake to assume that speaking in tongues is an evidence of one’s faith. To the contrary, the persons who seek signs and sign-gifts show their lack of faith. It is a sin for any Christian to seek for signs before he will believe God’s Word. As was pointed out earlier in this study, “tongues are for a sign, not to them that believe, but to them that believe not” (I Corinthians 14: 22). So you see, the Christians at Corinth were showing that they were weak in faith, and possibly some who identified themselves with the believer had never been saved. The person who seeks any sign, whether it be speaking in tongues or any other sign-gift, is either a babe in Christ or an unbeliever."

this is a bit worrying...