How do I deal with this etiquette on Facebook?

An acquaintance tagged me in a post about Easter Sunday and it looks as though I’m attending church with her – when in fact I’m definitely not, I was raised Jewish and I’m agnostic.

Would it seem rude if I untag myself? On the other hand, I really don’t feel like having a conversation with her explaining my agnosticism. Which will probably happen if she notices I untagged myself.