Hi, Congrats on this special milestone in your son's education! It can definitely be difficult to send one's only child off to school for the first time (a source of anxiety for many parents); with religion as one additional source of worry (whether because we fear or know that our child will be taught to worship a particular religious doctrine we don't believe in, or conversely, that we fear or know our child will not be exposed enough to our religious beliefs).

In your case, seeking a separation of church and state in the classroom, here is another similar JustAsk Q&A with insights from a licensed social worker you might also review: http://www.education.com/question/parents-professionals-suggest-dealing-teacher/ There are additional answers on that page from other parents, as well as extensive info from the asking parent regarding her concerns about Jesus curriculum being mandated to her Jewish son.

Consider also talking to the school's principal about your concerns to work out an educational alternative that meets state standards without compromising your family's religious beliefs. I would do this proactively, before school starts (if possible) and before an issue arises with a specific teacher. This conversation could also help the school in assigning your son to teachers that are a better fit for your family.

Below are some additional resources you may also find helpful:
 
Public Schools and Religion: What Parents Need to Know
http://www.education.com/magazine/article/religion-in-schools/  

The Parent's Guide to Kindergarten
http://www.education.com/grade/kindergarten/

Building Positive Relationships with Educators
http://www.education.com/topic/parent-teacher-relationship/

Childhood Immunizations and Vaccinations
http://www.education.com/special-edition/childhood-immunizations-vaccinations/

Homeschool
http://www.education.com/topic/homeschool-overview/

K12 - Online Public and Private Schools
http://www.k12.com/

Good luck -- I hope all goes well in your son's first and subsequent years of school.

This is a difficult topic, not only in school.  Should the ten commandments be on public buildings?  How about religions (some Hindus, for example) that have more than one deity, with the commandment to have only one?  Or as you are, with your right to be religion-free?

What we did was this:  we formed a group of concerned parents and met again and again with the school personnel, officials, and took it to the state legislature.  

It was worth the effort.  It took one year.  Jewish, Hindu, Buddist, Muslim, and other children were allowed time off for their holidays, and Christmas was replaced by a secular Winter Celebration; Easter by Spring Fling.  There was even more tolerance on the playground.

We respect various religions or lack thereof.  But in our land of the free, keep religion in the home, church, mosque, synagogue, or not at all if you please.

Peace, love, and good luck!

Hmmmm......your best bet would be homeschooling. You might not have noticed, but religion is everywhere you turn. Does your problem begin and end in school? What about the malls, and other venues. Would you raise a concern and stop shopping at those establishments?

If the teacher was actually making a biblical lesson plan I could understand and see your concern. As for "christmas around the world" that refers to how various countries celebrate the holiday. Would it make a difference if the teacher wrote "holidays around the world"?

I still say homeschool is your best bet.

send a letter to your superintended and board members of this thoughtless act that one of the teachers has done you don't have to let them know who its from but it has up set the students and some parents and needs to be handled

Maybe you could suggest that she either, includes religious holidays from around the world on her calender, which encompasses all major faiths and their festivals, ( without emphasising one),or none at all.
This would help the children appreciate cultural and religious diversity and the fact that we are all different but can still be friends. It opens up all sorts of fun art, music and dress up opportunities and classroom projects without forcing religious focus.