A good word from Herescope:
The power of the Gospel (Romans 1:16) lies in its ability to change the very nature of a sinful man into the image of Christ (Romans 8:29). And that power is not unleashed through persuasive words, psychology, shouting and sweating, miracles or a seeker-friendly approach. It comes only through the work of the Holy Spirit and modern preachers do more to hinder the work of the Spirit than to promote it.