It's nothing new to rant about how the secular holiday of "Christmas" always ruins the observance of Advent. I even know a priest who says, provocatively, "I don't celebrate Christmas. I celebrate the Nativity of the Lord."
But even among us who claim to observe Advent faithfully, fighting the influence of the empty promises of advertising and the importunity of Christmas lights and giant inflatable Santa Clauses, I think even we often fail.
This is because, as I hear over and over, Advent is "the time to prepare for Christmas." Well, yes and no. It's very clear from the readings and prayers for the first week of Advent that we aren't about preparing for the Nativity just yet. We're about looking forward to the return of the Lord in glory. But since, in a lot of ways, we have ceased to desire or believe in the return of the Lord, this doesn't mean much.
Even when we get to the second Sunday of Advent, we are aware of the judgment announced by John the Baptist. Indeed, the Incarnation we celebrate at the Nativity is a judgment; it marks the beginning of the judgment we bring upon ourselves by accepting the Gospel or not. But it's also about the final judgment.
Yes, the season of Advent is about preparing for Christmas, but this only becomes a specific and discrete spiritual theme along the way. In the end we really just trying to remind ourselves of a God who is adventitious by nature, appearing as the Other in the life of Abraham, in his Nativity, as our Bread, and as the glorious Lord of all at the end of time.