A. W. Tozer said the following in his sermon "In the beginning was the Word," the second in his sermon series on John. Tozer said that he was called a fanatic because of his emphasis on the supernatural fullness of the Holy Spirit (which he describes as an accusation of "stigmata"), his conservative (a.k.a. "fundamentalist") theology, and his premillennialism.
[The never-ending growth in the knowledge of God] makes the praise of man to be a pretty cheap thing to me. It makes me pretty careless of whether anybody likes me or not, or whether they’re willing to follow me or come to hear me; I’m pretty careless about the whole business. In the light of eternity and the long, long thoughts of God and the plans of everlastingness and perfection and the consummation and the coming of Jesus, I wonder what it all matters whether they like me or not. Yet there are Christians who are in mortal fear of offending some carnal old fellow. They wouldn’t draw blood lest somebody would say they’re fanatic. There never lived a good man in all the world yet that some . . . child of the devil didn’t say he was a fanatic. . . . Some people would rather die than be called a “fanatic.” . . . But in the light of eternity and the long, long reaches, I wonder if it matters very much anyhow what anybody thinks about me.