Two Christmases

    

People from non-christian countries tend to see Christmas as a christian festival but it is more complicated than that.
Of course it is a christian religous festival celebrating the birth of God made man. However stories of the birth are contained in only 2 of the 4 biblical gospels describing the life of Jesus Christ and they differ on the aspects of the story they tell.
When the Romans stopped persecuting christians and adopted christianity as the religion of the empire (some hundreds of years after the time the events were supposed to have happened) they grafted the celebrations on to a pre-existing pagan festival to celebrate the winter solstice.  Northern countries had always held a big mid-winter festival ,to celebrate the days lengthening, and because there is not much work you can do in short ,cold days and you want to stay inside , round the fire, and have a feast to cheer you up.
So many practices associated with local pagan festivals were adapted to celebrate Christmas and given new christian "meanings". Also with the growth of free market capitalism and cities christmas became a major marketing event and various new "traditions" grew in the 20C associated with this.
Britain is an increasingly secular country. Whilst many people may keep the religous traditions and look for the "real christmas"  within the other christmas  razzamatazz, many people just keep the merrymaking traditions without complicating them with any religous belief.
There will be lots of children who know nothing of the christian christmas story of the  birth of Christ, but except in extremely religous non-christian families there will not be a child under 7 who does not believe in Father Christmas.