I think it's very important to be polite and considerate to other people. I'm not sure about the "respect" word, because to me it sounds a little deferential, but certainly consideration and politeness.
Which would include not challenging people about their faith unless I felt it was potentially damaging to someone else or was having a direct impact on me or someone else, or if I was in a discussion/argument about different beliefs.
But how far does this go? Do I have to be polite and considerate about people who believe in horoscopes, or Vedic flying or the Great Arclesiezure? Or can I restrict it to the world's great religions?