What we find in Rohan is troubling. Théoden seems demented and paranoid, distrustful of those who love him and are loyal to him. Théoden is also submissive and yielding to the advice of Wormtongue, his advisor.
We soon learn that Wormtongue is a servant of Saruman and that Théoden has been under a bewitchment. But Gandalf has come to break the spell and rouse the king.
As Fleming Rutledge observes, the transfiguration of Théoden is one of the great transfigurations in a story with many great transfigurations. A confused, senile, paranoid and docile old man becomes a sane, powerful, and fearsome king. The change is not unlike that of the Gerasene demoniac in the gospels.
And Wormtongue is aptly named. The bewitchment of Théoden was produced and maintained with poisonous words, with flattery, insinuations, half truths, and lies.
It's noteworthy that Satan is called "The Father of Lies." The devil traffics less in lasciviousness than in falsehood. I think this is so because life is, fundamentally, about moral navigation. And if you can't see the world and yourself truthfully and accurately there's no way to chart a course.
This seems to be one of the reasons why our world is so lost and sick. No one knows what is true anymore. No one can agree on what is true anymore. We are bewitched. We are Théoden.
