The Obama administration has directed the military to not allow personnel to say “Christmas”, in spite of the holiday’s status as a federally-recognized holiday.
The reason given by armed forces officials is that not everyone celebrates Christmas and that out of respect for them, military members should refer to Christmas celebrations simply as “holiday”-themed festivities.
This prohibition comes in the context of a wider push for political correctness in society in general and the military in particular, as evidenced by the recent reprimanding of Navy Chaplain Wes Modder for simply discussing religion, as chaplains are wont to do, with military personnel.
See how servicemen have reacted to not being allowed to say Christmas at the link below:

Hey Obama god still loves u all u have is give your heart to him and u should get on your knees confess your sins give your life to Christ god sent me to tell u this for I am one his warriors
MERRY CHRISTMAS!!!
FO Obama! This America and you don’t belong here! So GET OUT!
Merry Christmas
Are you people really this stupid?
So ridiculous. Free speech entitled the military to talk about their faith
False
Maybe he should go after the F word it is offensive to me.
Not so fast…http://www.snopes.com/obama-military-christmas-ban/
Merry Christmas Barack Obama! Just because my God is an awesome God and loves YOU too!