The term "evangelist" gets used a lot by tech companies as a job title to describe those who try to push knowledge, use, and acceptance of a product, service, or company in a way which promotes the product/service/company. I was wondering what would be appropriate antonyms for this sort of usage. Given the very literal definition of relating to religion by most online dictionaries and thesauruses, antonyms are either not appropriate (such as layman) or non-existent. Given the pretentiousness of the term, I think an equally "weighty" term is most appropriate as an antonym.
Words that came to mind were: denouncer, antagonist, or decrier. I'd be interested in any thoughts on these terms as antonyms or any other suggestions.