We are an atheist/agnostic household that does not attend religious services, but one side of the fmaily is very religious and my children have many friends from religious families. One thing I have found helpful is to compare religious beliefs to other beliefs my child holds very dear, such as environmentalism or being extremely kind to animals (DD verges on PETA material). She would not want to hear someone talking disrespectfully or with great skepticism about these core beliefs of hers, so she needs to speak respectfully regarding others' beliefs even if she does not share them. Within OUR household, she is free to question and discuss. It's not a perfect parallel, but has helped a little.
