Because I would have to have a reason to think otherwise.
But you are making the positive claim here. How many other things do you have no evidence of non existance of?
Do you have evidence of the non existance of Kali? By your logic you have no reason not to believe in Kali, have you?
If I have positive evidence ofr something
But you have no positive evidence, have you? One can interpret the bible as factual (to what degree I won't assume) but the strength of the evidence relies on an a priori assumption that what the bible says is correct.
Circular logic, in this case.
Every alternative can turn out to be true, but will be more unlikely the less you have evidence for it.
What you seem to be ignoring is the strength of the evidence. When I supervise students writing essays I make a big point of saying not to rely on secondary evidence.
Someone using the bible (that is secondary evidence) is on vaery shaky ground considering the fantastic claims it makes.