Let us suppose that Smith dislikes Protestantism, and wishes to discredit it.
Smith could, of course, simply begin arguing against it openly, showing where he believes it to be in error whether on a Biblical, historical, or philosophical basis. Many folks do this, with varying success.
Alternatively, Smith could be devious. He could set himself up as a protestant apologist, vigorously defending various positions of the reformation. Or, at least, seeming to do so ... when in fact, Smith is gradually following them to their logical conclusion in a sort of “reductio ad absurdum”. Before too long, Smith is upholding positions which are intolerably arrogant, self centered, and disingenuous ... yet he has impeccable protestant credentials. He’ll get nothing but “Amens” and “Huzzahs” and “Dear Brother” from the other protestants ... yet he has succeeded in making them look ridiculous.
It would be brilliant.
Just sayin’
Sure, they’re called “Jesuits”