Humor can be very serious as a pedagogical tool. It is not necessarily flippant or trivial. The Bible is full of humor. Church history is full of those who used humor for good. (Athanasius, Martin Luther, John Owen, Charles Spurgeon, and G.K. Chesterton spring to mind as just five of the more obvious examples.) Humor is often predicated on mental switches, on leading the mind one way and then suddenly springing a trap or doing something unexpected. In other words, it can make people think.