'Reality' is already being taught even if it contradicts some religions. The important question is how far do you want to go with that? Personally I feel it's ok for a tecaher to explain all about earth's 4-billion year timeframe etc., even if some Christians say it sin't so (I beg to differ with them on that one). I do not think it's ok for any teacher to say God doesn't exist, as that is something that cannot know; moreover if they insist on empiricism for their world model, they should also realise there is no empirical evidence to prove their belief.

I once had a teacher who dismissed the Holy Spirit as a pigeon (He's represented as a dove in old paintings). Now there's no way she can say for certain there is no such thing as the Holy Spirit, but she was presenting her belief (however well-founded) as fact. Moreover, she was missing the point - the Holy Spirit is a spirit, not a pigeon. This is only a representation in art, a symbol. I felt like standing up in class and saying "Miss, you're right - and the United Nations is just a bunch of leaves and wood!" (maybe I wasn't too far wrong either!) But being a small boy against the 'might' of the teacher and realising from her tone it wouldn't have gone down well, I kept silent.

And where did the rain come from?