I believe that my faith is true. That's good enough for me. In my faith, faith is what's important. I don't think it's arrogant to say "I believe my faith is true" at all. No one would follow a faith if he or she didn't believe it. I don't even think that first answer is arrogant, since the statement does indeed say "I'll never change to disbelieve my religion" and it's not saying anything about anyone else believing in it.