If they don't believe in hell and they have no doubt about their beliefs, whatsoever (they often claim they do not), why would it bother them if a Mormon/Muslim/Jew/Christian/Hindu said that they believe that those who disbelieve in their religion will go to hell?
I have heard multiple arguments from Christians that Muslims will go to hell. This has never made me feel the slightest discomfort.
I have heard multiple arguments from Christians that Muslims will go to hell. This has never made me feel the slightest discomfort.