Here's a great insight from Dale Ralph Davis (writing on 1 Samuel 22, which is a long poem David wrote):
Now David could have "studied brevity" here. Instead of the 69 Hebrew words or the 141 English words (NIV) in verses 8-16, he could simply have written "Yahweh intervened on my behalf." (five words). Why didn't he? ... Although such a statement would be factually true it would not be impressively true. David doesn't merely want you to tell you a fact about Yahweh, he wants you to see Yahweh in all his saving fury.
I think that's a big part of the difference between preaching and lecturing. It amazes me that it took me so long to realise (i.e. up until a few years ago) that the way things are said conveys as much information as what is said.
This dilemma reminds me of the time someone, apparently in Philadelphia, asked George Whitfield if he might print his sermons. Whitfield replied "Well, I have no inherent objection, if you like, but you will never be able to put on the printed page the lightning and the thunder."