I'm not a particularly spiritual man, but I do understand and respect the need for religion in a healthy, prosperous society
Christmas probably started like many holidays, in this case: as common pagan celebration of the winter solstice. Christianity comes along and seeks to spread the word of God/Jesus/Whoever. so the missionaries essentially tell the pagans they preach: "You can still celebrate your festivals, but we would be honored if you celebrated in the name of Christ." And thus the winter solstice festival becomes they day Jesus's birth is celebrated.
many of our common holidays got their start like that. Pagan celebrations adapted for the word of God.
I will not deny that this season is steeped in commercialism. It's not all bad, as long as we don't get carried away with it.
If you enjoy the commercialism of Christmas and can afford it, by all means go and spend! In this economy, one of the best gifts you can give is the gift of business for a small store that needs it. There is nothing inherently wrong with the commercialization of Christmas as long as it doesn't get out of hand. Many businesses need this season.
Its up to the consumers to not loose track of where it all the hype comes from. At a local church I attend occasionally, the most heavily attended period in the entire year is during the Christmas --or advent, as they say-- season.
Its a delicate balance, between a religion and the economy, Christian philosophy would suggest that we honor both: honor the day set aside to celebrate the birth of the Messiah, and honor the local business that it may continue to employ good people.
anyways, that's my two cents on the whole Christmas thing.