KK - Christmas has many and complex origins. Older traditions and beliefs have been co-opted, appropriated and re-framed by religions, by commercial organisations, by literature and embedded in secular 'traditions'. Fundamentally, most people are not deeply religious, if they're religious at all, but most tend to celebrate Christmas as a shared, cultural event. It's no bad thing IMO. I bet you 'celebrate' the world cup, or whatever happens to be your bag. It's the same, in that it's a time that everyone joins together in a collective, cultural ritual or celebration.