Nonsense. If you are a religious person, then you believe your religion to be true -- more than that, you know it to be true. You also know the beliefs of other religions to be false. If you know something to be wrong, then why respect it? I'm not saying to disrespect the people, but certainly do not respect beliefs that you know to be false.
Being respectful of another's beliefs implies that their beliefs hold as much value as yours do. If you know your beliefs are true and theirs are false, how can you possibly hold to the idea that they're of equal value? I do not respect the belief of someone who insists that money literally grows on trees, and nor should you respect the belief of someone of a different faith (that you know to be wrong).
The only way theists can honestly respect beliefs they do not share is if they subconsciously do see them as being of equal value -- that they're based on the same weight of evidence (none), possess the same logical support (none) and represent the same amount of truth (none). If theists truly accepted their faith as being 100% certain, then they would be incapable of respecting the beliefs of others (just as they are incapable of respecting the belief of a lunatic who insists he is Napoleon -- to a 100% devout Catholic, the beliefs of Islamics or Hindus are just as alien).