“Good sermons require some art, some virtue, some knowledge. Real sermons require some special grace which does not transcend art but arrives at it by instinct or 'inspiration'; indeed the Holy Spirit seems sometimes to speak through a human mouth providing art, virtue and insight he does not himself possess: but the occasions are rare. In other times I don't think an educated person is required to suppress the critical faculty, but it should be kept in order by a constant endeavour to apply the truth (if any), even in cliché form, to oneself exclusively! A difficult exercise.Letter 63””
The Letters of J.R.R. Tolkien