Christmas in Schools?

Should we celebrate Christmas in schools? So many schools are turning away from this idea and banning the celebration of this holiday, to be fair to all faiths. I do not agree with this. America was founded on Christian beliefs, but we are slowly getting rid of all things Christian in society! It is unbelievable to me. I do not see what is wrong. We are supposed to teach about different cultures, but we can't teach about our own? I try to celebrate an array of different holidays in my classroom, and love to have parents of students with a different culture than my own, come and speak. What do you think? Should we take Christianity out of schools?