Sentimentality is subtle. C.S. Lewis once told a young writer: “Instead of telling us a thing is ‘terrible,’ describe it so that we’ll be terrified. Don’t say it was a ‘delight,’ make us say ‘delightful’ when we’ve read the description. You see, all those words (‘horrifying,’ ‘wonderful,’ ‘hideous,’ ‘exquisite’) are only saying to your readers, ‘Please, will you do my job for me.'” Lewis complains that authors of gushy and sentimental words are tyrannical because they tell the readers how they must feel rather than letting the subject work on them in the same way it did the author. Sentimental worship leading works in exactly the same way that Lewis describes. With typical comments–“Isn’t he just wonderful?” “Isn’t it such a blessing?”–the leader tells people how they ought to feel about God instead of telling them about God.

Tim Keller, in his chapter “Reformed Worship in the Global City,” Worship by the Book, ed. D.A. Carson; Zondervan, 2002 .