During the course of a 45 to 60 minute "Bible study", it's amazing (and disheartening) to think of how little of that time is spent actually looking into the text.
Sure, the sermon is usually based on the text for the day, but it is sort of a platform on which the preacher stands, rather than the ultimate end.
Perhaps the Catholics are right to keep it down to a out 10 minutes... At least they've spent an equal or greater amount of time doing what is the supposed goal of Fundamental Evangelicalism--"simply teaching the Word of God".
Take a sermon I recently heard, based on a chapter in the Gospel according to John. The chapter was 42 verses. Let's say the sermoner spent 10 seconds reading each verse (although it's generally closer to 5 seconds). That's 420 seconds, or 7 minutes. Then, each 5 to 10 verse section gets about 2 minutes of application. That's 8-16 minutes. Let's say 15.
So, we have a total, so far, with simple reading and application, of about 22 minutes. And that's if he's reading slowly and you're in a long chapter!
So, what's the rest?
This reminds me of one time, when I was young...
(If only my illustrations were that engrossing!)
Stories. I know I've done it. I'm not condemning anyone here. I'm saying that, perhaps, a Sunday morning service is not the time to drag out all of your old stories, even if "The Time Grandma Hit a Cat with the Lawnmower" really does emphasize your main points about Jesus healing a blind man.
So, how long should sermons be? I don't know. Who should we emulate? Who is good at making a point and not rambling?
Read a parable from the Gospels. See how long it takes you to read it aloud in a conversational voice. You're looking at about 2 minutes for most of them.
And Jesus never had a problem getting His point across!