I feel very misunderstood whenever I talk about religious fanatics. Religious fanatics are not the same as religious people. They are the opposite of religious people.
A fanatic’s only allegiance is to her or his own interests. A fanatic’s only God is his or her own self. There would be nothing bad about it if only fanatics admitted that honestly and didn’t try to pass of their self-interest for something that is supposed to benefit all humanity. Why do you think the Soviet Communism soon acquired extremely religious overtones? That was because the Soviet Communism shared with religious fanaticism the crucial quality of complete self-righteousness that knew no moral barriers and experienced no qualms.
A religious fanatic is a sociopath who finds blabbering about God very convenient to dupe the simple-minded into putting up with the fanatic’s exploitation and nastiness.
Religious people worship God. Religious fanatics believe they are God.