1 Corinthians 6:12 says "All things are lawful unto me, but all things are not beneficial: all things are lawful for me, but I will not be brought under the power of any."
Christians have liberty in all things. (Note that liberty is not the same as license, but thats a discussion that could easily take up a whole thread of its own.)
The questions Christians have to ask ourselves are: Is what we want to do beneficial? Is this thing we want to do drawing us away from serving the Lord?
Celebrating Christmas is wonderful for my family and me. It is beneficial in that it brings us a great deal of joy, and gives us an opportunity to set aside time specifically to ponder what He sacrificed merely by choosing to be born a tiny babe rather than coming as a warrior on a white horse. Certainly, rather than pulling us away from the Lord, this celebration draws us nearer.
Friend, I believe you're taking "liberties" with that passage, by reading it completely out of context. :)