NT Wright on the power of the Holy Spirit and the sign of speaking in tongues:

Some people try to sweep ‘tongues’ aside as if it was a peculiar thing which happened early on and which, fortunately, doesn’t need to happen any more. Sometimes this is combined with a sense of the need to control the emotions, both one’s own and other people’s. But ‘speaking in tongues’ and similar phenomena are, very often, a way of getting in touch with deeply buried emotions and bringing them to the surface in praise, celebration, grief or sorrow, or urgent desire turned into prayer. It is hard, seeing the importance of ‘tongues’ in the New Testament, and their manifest usefulness in these and other ways, to go along with the idea that they should be ruled out for today’s church.¹

¹  Wright, T. (2008). Acts for Everyone, Part 1: Chapters 1-12 (p. 24). Society for Promoting Christian Knowledge.