Staying on the topic of Religious Philosophy versus Religious Practice let's look at the ideas behind Christmas.
The history of Christmas is quite fascinating. Since our earliest recorded history the time of year when the days stop getting shorter and the sun "returns" (the Winter Solstice) has been celebrated in the Northern Hemisphere.
No matter what the practice surrounding the celebration (whether sacrificing the mock king to assist the god Marduk in his battle against the forces of evil, the sending of scouts to report the return of the sun to the dark northern skies or what looks like just plain ole partying by the Romans during "Saturnalia") the essential message was one of hope for the future.
It wasn't until the 19th Century that what we now think of as the Christmas tradition began. What happened essentially was that by creating popular literature about a "tradition" that didn't really exist, the tradition was brought into being. This new "tradition" stressed the importance of helping others not so fortunate as ourselves and good will towards all mankind.
Despite the commercialism of modern day Christmas, I think those three messages of hope for the future, helping others and good will towards all, still manage to cause good things to happen at this time of year.
So no matter what your religion, if you recognize the philosophy behind the practice called "Christmas", you can join in a celebration of those three messages and better yet, you can practice them in whatever way you wish according to your beliefs.