I found another couple, IMO, excellent statements/questions to use when they start their hounding.
First I say, "Let's look at the Bible, and see what is written there about what you are saying." Usually they will decline, as they do not want to get into any kind of debate they will likely lose. When they decline I ask them, "Don't you respect what the Bible says?" If they answer "Yes', then I continue using the Bible to refute their intrusion into my business. If they say "No" they have effectivcely denied their own beliefs, and I tell them so.