The No True Scotsman Fallacy

The church says any happiness that we don't approve of is by definition evil and counterfeit. The church does this nonstop in conference talks, where they take words and put special definitions around them. And so when you're in a debate with them, then they have defined happiness to be whatever they say it is. So from a rhetorical perspective, if you can be the first to define the terms, then you can control the debate.