It's absolutely impossible to reason with people like that, and I have to imagine you're already well aware. Evidence means nothing when "belief" can replace it.
He said, and it amuses me to this day, no one takes the creation story literally!
So there he was, in a strong relationship with a sister who he had known his entire life and didn't know that she took the creation story literally whereas he took it more poetically. And they grew up in the same household.