ok, as this is obviously confusing for you....
someone said that the difference between da vinci code and bible was that one was intended as work of fiction, whereas the bible was written to be fact. however, intents alone do not justify a work, as the qur'an was written as fact too. If the defense for either of those texts is "well, it was written to be fact" then, if thats the whole reason for their validity, you must then accept them both as accurate. the problem here is that they are then contradictory.