As a Christian, I can completely relate to your sentiment. I've found Christians to be the most closed-off, narrow-minded group of people, distrusting and even downright antagonistic of anything that sounds "non-Chiristian."
As a Christian, I'm sorry you've been hurt. It's not right.
Supposedly Pilate pissed off the Jewish population repeatedly in his governorship by pushing Roman religion and minting coins with non-Jewish imagery, so I think we can safely say he wasn't Jewish and was presumably Greco-Roman or Mithraic.
I think he's saying that because the original cult would have considered themselves Jewish the Pharisees (understood within the text to be the contemporary Jewish theocratic leadership but it's a bit more complex in reality) arguing for his execution are basically the same thing as Christians.
Which is silly.
I assume he lost the context of the argument or wasn't raised in... Any Abrahamic faith because wow.