The novelist and essayist Haruki Murakami wrote quite a bit, based on interviews he did with survivors and cult members, about the Aum sect, who released deadly Sarin nerve-gas on the Tokyo subway in 1995. His interviews and his thoughts appeared in English in the book "Underground".
He promised to return to the matter of cults in his fiction, which he has done in his latest work, IQ84.
In it appear two cults, one is "Aum like", with a very sinister leader, the other is a christian sect whose pamphleteering members refuse life-saving surgery and is called "The Society of Witnesses", I wonder who inspired the latter one ?