Sentence:  The more strongly people felt about their ideas, the more potent the demons seemed to them: Christians believed that traditional paganism, far from being the work of men, was an 'opium of the masses', pumped into the human race by the non-human demons; and one scholar even ascribed bad reviews of his book to demonic <WSD>inspiration</WSD>! 
Meaning of the word marked with <WSD> tags:  A supernatural divine influence on the prophets, apostles, or sacred writers, by which they were qualified to communicate moral or religious truth with authority; a supernatural influence which qualifies people to receive and communicate divine truth; also, the truth communicated.