Francis Bacon’s dictum is correct: “Reading maketh a full man; conference a ready man; and writing an exact man.” In the pulpit we need to be exact men, for we who teach will be judged with greater strictness (James 3:1). Moreover, sermon delivery will inevitably affect sermon preparation (Tinetti, 59). If a man (even subconsciously) intends to waste time telling stories and anecdotes where concision and brevity would serve just as well, then he will know that he does not need to prepare as much Biblical doctrine and content during his preparations. Not writing a manuscript (whether in full or part or in detailed outline) may exclude for him a heavily doctrinal or scriptural product. Except in the case of exceptionally talented speakers, a consistent failure to write will lead to inexact and prolix sermons that tend toward fluff and filler and repetitiveness. Reu, a proponent of writing and then preaching from memory, rightly asks (Homiletics, 520):
Why is it that mature preachers who, after writing for many years, have taken to extemporisation, resort to writing and memoriter delivery on extraordinary occasions and when they have to face a specially critical audience? It would seem that what they consider the best method for such occasions ought to be their standing rule for all occasions. The souls of men are before them and God is present, Sunday after Sunday; and these surely deserve no less respect than festival occasions and critically minded audiences.