Singing to praise, singing toward heresy

I am convinced that congregations learn more theology (good and bad) from the songs they sing than from the sermons they hear. Many sermons are doctrinally sound and contain a fair amount of biblical information, but they lack that necessary emotional content that gets ahold of the listener's heart. Music, however, reaches the mind and the heart at the same time. It has power to touch and move the emotions, and for that reason can become a wonderful tool in the hands of the Spirit or a terrible weapon in the hands of the Adversary. Naive congregations can sing their way into heresy before they realize what is going on.
- Warren Wiersbe, Real Worship, p. 137