I hear you, but they're not synonymous. Plenty of religious zealots are that way because it's an easy avenue for control over others, and how much they believe of their chosen religion is an open question. If it's a sliding scale of mental health issues, religious zealots are closer to 'just get therapy and deal with some shit' than 'needs medication to understand that their neighbor, mail carrier, coworker, and that random guy that passed them in the street aren't colluding to ruin their life.'