Living at home, can my mother tell me I can't practice my religion in her house even though I'm an adult?

Honestly, I think she is in the wrong. Her house or no, she has no right to destroy your personal property, nor does she have the right to try and control what you believe. She can make rules about not practicing your religion in her home, and you should unfortunately respect that, even if you don't agree with it. Communication and getting her to see that there is nothing evil about your beliefs would be ideal, but if that is not possible, I would just keep a low profile until January. Hide your books!