Many religious conservatives complain about how liberals are trying to take Christianity out of Christmas, but should Christmas even be in Christianity to begin with? There are Christians today who say that it shouldn't. This anti-Christmas attitude used to be much more common within Christianity and maybe it's a sign of the influence of modern culture that things have changed so much.
Santa with Crying Child, 1930
It's ironic that Christian railing against secular culture's influence on Christmas is happening in part because secular culture has gotten Christians to make a big deal out of Christmas in the first place.
The News-Sentinel in Fort Wayne reported a couple of years ago (the original is no longer available):
The nation's one million Jehovah's Witnesses also don't believe Dec. 25 is the correct date. "It has been established to our satisfaction that is not the birth of Jesus," Backloupe says. The Church of Christ, which has two million to three million members, also doesn't believe Jesus was born Dec. 25, pointing to the Bible's indications that Jesus would have been born in a warmer time when the shepherds would have been out in the fields to see the star that reportedly heralded Jesus' birth.
Although the great majority of Christians worldwide now celebrate Christmas on Dec. 25, they have not always agreed on what kind of celebration is appropriate. Even in the early days, church leaders were concerned about too much merrymaking. The church's Second Council of Tours proclaimed in the mid-500s the duty of fasting during Advent and the sanctity of the 12 days between Dec. 25 and Jan. 6.
In the 1600s, Christmas came under strong attack from some Christian groups. The Puritans banned Christmas because there was no reference to it in the Bible and even fined people who celebrated it. The English Parliament also outlawed celebrating Christmas in the mid-1600s. But their view wasn't shared by all, and as more diverse groups came to the United States, Christmas became more festive for most Christians.
I certainly have no problem with Christians who choose to celebrate Christmas, either as part of their liturgical calendar or simply as a cultural event. The fact that Christmas arguably isn't fundamental to Christianity, and may even be antithetical to aspects of it, does however mean that Christians shouldn't get self-righteous if contemporary American culture has drained the holiday of many religious elements. If Christians could drain pagan meanings from it, why can't modern American drain Christian meanings from it?
Holidays aren't static. Holidays serve social and cultural needs, which means that as society and culture changes the manner in which we celebrate our holidays also changes. The "traditional" Christmas people like to reminisce about is of relatively recent vintage, with all of the elements not coming together until the 20th century and many elements not even starting until the 19th century. There is nothing permanent or necessary to the way we celebrate Christmas today and Christians don't have much basis for complaining when changes occur.