The teacher using those grown up words is out of whack. I'd meet with her to try and figure out where it's coming from and what her expectations of a 6 year old are.
Your child should not be marked down at 6 for not knowing about religion, that's absurd.
At the same time where there's smoke there may be fire. Perhaps your child is not doing as well as what you thought/the teacher has valid concerns (even if she's done a shizen housen job of expressing them). Hopefully you can get to the bottom of things with a meeting.