Truth is what the verifiable facts say it is. Truth lies in the direction that the evidence leads. If a person is presented with facts and evidence and still chooses not to believe the truth, or to pursue corroborative evidence, then he is no more than a shrew doomed to be the prey of con artist wolves and charlatan jackals.
If one is presented with truth based on verifiable evidence and fact and then chooses a position contrary to this position then any claims made on that argument are absolute nonsense. Any premise contrary to this truth must be false and subsequent argument is rendered moot.
In other words:
If one creates an entire belief system based on a false major premise then the entire belief system, no matter how staunchly defended, can be nothing more than utter nonsense.