I know that "Truth Questions" technically fall under the scope of "Primarily Opinion Based" or "Too Broad" and not "Off Topic," but to aide in the training of new visitors, and to reduce the need to manually repeat the common rant about why Truth Questions, and "Is X a sin?" are not a good fit here, wouldn't it be simpler to add a blurb about Truth Questions to the list of Off-Topic close reasons?
Possible wording for such a close reason:
Questions asking for the truth or validity of a particular doctrine or belief (aka Truth Questions), and questions asking Is X a Sin? are not a good fit for our site, due to their subjective nature, and the vast number of possible Christian opinions on such topics. See: Relevant meta post