This is a great question - and one I've been thinking about since this site came into existence. I'm well aware of the Parenting policy (What should we advise when one disagrees with the premise of a question?) and I think it's really valuable and that we should respect the users' decisions when they post. I fully support having a similar policy to what is outlined in HedgeMage's answer there, particularly this part:
In these cases, I feel it is best for the offended party to pass the question by. If one doesn't practice $whatever, then one is not likely able to provide expert-level advice on it. All that is accomplished by soapboxing is to create a community with an agenda, instead of a community that provides information. I believe that responding to "How do I $x?" with "Doing $x is inexcusable and/or evil." is inappropriate, and should be dealt with using downvotes and/or deletions to prevent shrill bickering over our differences from obscuring useful information that the questioner is seeking.
Most importantly, it is never appropriate to post an answer that does not directly answer the question asked.
Let's look at a couple of similar examples:
- How to tell friends something goes against my religion?
- How to ask a vegan to stop telling me about veganism because I am not interested in it?
These are similar but somewhat opposite questions.
What we don't want is someone arguing with the person asking's closely held beliefs. In neither example would it be appropriate to tell them "don't believe that, it's wrong." We're not here to discuss religion or dietary choices. Answers that only say "don't do that because you're wrong to believe that and here's why" should be downvoted and deleted. They are Not an Answer.
So, in the case of the former, writing an answer that says
Switch to my religion. We get to cuss as much as we want and we have cookies!
Isn't an answer and should be deleted.
And in the latter, answers that argue that veganism is the only diet anyone should be following and that the OP needs to reconsider their decisions are also NAA and should be deleted (and have been).
I would also recommend that an answer that both answers the question and tries to argue that the OP is wrong in their choice should be considered closely and possibly edited to remove the latter part if it is completely irrelevant to the answer. In this way we can preserve good content without starting arguments over these subjects.
When reviewing answers of this type, though, we should be careful when it comes to answers that say "don't do that" not because the beliefs are wrong but because the reaction to the interpersonal situation is wrong.
In the first example, the question is asked:
My religion prohibits me from being profane, how can I tell my friends to stop swearing so that I am not influenced by their actions?
The very appropriate top answer responds:
You don't. You can't expect other people to follow your religion. If you phrase your request like that, it will likely feel to them like you're asking them to adhere to the rules of your religion.
What you can do, is ask them to refrain from swearing around you because it makes you uncomfortable. You may explain that it is because of your religion, but you really should stress that is making you uncomfortable.
SQB's explanation shows that it's not the religion that is problematic but the OP's command that his friends comply with a religion they may not share.
Similarly, in the veganism question, were someone to write an answer saying
Don't ask them to stop again because you've already done so and they are ignoring you. They're harassing you and it's time to go up the ladder to HR.
This is an acceptable answer, despite telling the OP not to do what they seem to wish to do in the question.
The Parenting question addresses a third issue, which I'm not sure we've seen here, necessarily - when the question is based on objective "facts" that are blatantly wrong.
In this case, I think that the top Parenting answer comes up with a good solution - to question the "facts" (in a polite way) in a comment to see if there is a misunderstanding.