Say the word "demon" and the first thing that might pop into your mind is the image of a child you know. Sometimes we describe an ornery child as "a little demon." But in the Bible, the word demon is never used that lightly. It is a word that is always used seriously and fearfully to describe one of the forces of evil, an unclean spirit.

Saint Mark records for us the story of one demon who filled a father’s life with agony because of the way he possessed the man’s son. Shortly after the Transfiguration of our Lord, a man came to Jesus with a pitiful request. "Teacher, I brought my son to you because he has a spirit," the father said. The demon used to seize the boy, dash him to the ground, make him foam at the mouth, and grind his teeth. It would cause his body to become rigid all over. A…