I once took a three-day summer course from a teacher at Princeton Theological Seminary, who was a fairly intimidating figure. There was one thing he said that intimidated me much more than anything else. He said that when he taught a full-semester course on preaching, as opposed to the three-day easy one that I took, he insisted that no one could pass the course unless they could memorize the entire Sermon on the Mount and stand up in front of the class and deliver it. For those of you who haven’t checked lately, the Sermon on the Mount runs nonstop for three full chapters in the Gospel of Matthew, about…