"The Truth" that is claimed to be revealed is one which is claimed to have been revealed by God, the Creator, who was there at His Creation event. Now you can certainly claim that God did not reveal that this is how it all came about, but then it's not possible to prove a negative, is it??
So the creation story is either a truth revealed by someone who was there as a partaker of the event, or it is a lie. Certainly we cannot be so wise as to claim that we know which one is true. I choose (freewill after all) to believe the former. It seems reasonable from what I see in the universe. It feels right in my soul. Those two things are what I base my decision on (my "gut" feeling combined by my personal observations of the creation)...