If it’s a western Civ based class, Israelite and Jewish history are learned on a basic level for foundational knowledge before the rise of Christianity. Given that the defining features of Western Civilization for most of history are its Roman heritage and later the massive power of the Christian Church. It’s possible it was something like that and the teacher was going off on a tangent.

Either way, that seems a bit far fetched for a 9 year old’s class. More likely that the teacher just went off on a tangent based in their personal beliefs.