Try asking plain GPT-4 for a Bible verse in Greek. It will recite it for you accurately from memory.

I recommended a friend who is an engineer-turned-Catholic-priest take a look at it, and he was quite impressed with its ability to answer theological and philosophical questions; as well as its ability to explain the grammar of the Latin translation of a Bible verse (which it had recited from memory).

All that to say: I don't think you needed to feed it the KJV. :-)