It is all evidence whether it is fiction or non fiction.
This is incorrect, but it is a helpful statement in determining how you have gone so far astray.
Fiction is not evidence of any kind unless the truth being sought is also fictional.
For example, to play on the "let's use an X-men comic" angle from before.
Let us say that the truth I am seeking is whether or not Wolverine has claws. One could make a value judgement on this truth (it
is true) using evidence found in comics and statements by the authors of the comics, as well as other media in which the character has been portrayed (Wolverine: Origins, shitty as it was, would be your best primary source because it shows that he
naturally has claws). The truth I have validated is evidentially true
within the context of fiction (things that are not factual or empirical).
However, Wolverine does not exist. Furthermore, mutants (in the X-men sense) do not exist. I cannot use X-men comics or movies to prove that mutants exist, because they are fiction. All of the evidence I draw from to prove that mutants do not exist is non-fictional.
Thus, you have two options:
1. Posit that the bible is evidence for the existence of God, but fictional, and thus indicative of God being fictional, just like Wolverine
2. Deny that the bible is evidence for the existence of God, and adhere to the principle that belief in God is predicated on faith alone.
I recommend the second option. No matter how much evidence is uncovered by science, it will always be valid.
It is proof. Yes. Is it true or not true. That is up to you and I to believe one way or the other.
Incorrect. Proof, by definition, is evidence of sufficient quantity and quality to establish truth. Proof cannot be untrue, ever.