Peace Emawk,
Having access to information is a gift and a curse.. because once we have that information, we're not always sure what to do with it.. so we fall back on the simplest modes of analysis.. the yes/no, either/or.. good/bad mode... That said.. Christmas parties are not about Christmas.. they are just events where people get together during this time of year. Their are no christmas rituals that conflict with your beliefs at the christmas party are their? If your reasoning is that because of it's not in the bible, I can't participate, then your list of things that you cannot do must be particularly long. Birthday celebrations are not in the bible either.. neither is mothers day.. nor so many other ritual celebrations and cultural functions that you directly or indirectly participate in.. If you are truly serious about the bible, you will have to change your life completely.. where you live, how you live.. who you live with, etc.. What does the bible say about girlfriends? I'm guessing you don't want to take it that far right? so, look, if there is nothing going on at the party that conflicts with your belief system, then what really is the problem with attending the Christmas party with your girlfriend?