Some evidence suggests that Christmas itself was merely a reappropriation of the pagan festival of Saturnalia. If that is in fact the case, my godless Christmas is more an insult to ancient Romans than to Christians. Since there aren't too many of them left, I won't let it worry me.
The best thing we nonbelievers can do, in fact, is be honest about not celebrating the religious side of Christmas. Each Christmas and Easter, churches have to struggle to accommodate the extra crowds who show up for holiday services. While pews may be partially filled or even deserted on a Sunday over the summer, the holidays see a huge increase in attendance as the CEOs (Christmas and Easter Onlys) stop by. The problem is particularly pronounced in Catholic churches, as Christmas is a holy day of obligation. When holiday church attendance is motivated by guilt instead of a genuine state of religious worship, it creates headaches for everyone—and takes up valuable pew real estate.
Instead of sitting in church, feeling uncomfortable and vaguely dishonest, I can spend the day with my family—sleeping late, opening presents, preparing and devouring the Christmas meal, sipping a beer, watching the inevitable holiday Law & Order marathon. Could I do these things at other points of the year? Sure—Law & Order is a year-round pleasure. But only at Christmas do so many of my friends and family also have time off, and only at Christmas can I see loved ones who have scattered across the country. Whether or not you believe in God, Christmas is a time of year when you head home or host guests, a rare occasion for the kind of togetherness that can drive you crazy, fill you with love, or both.