I suspect there are some who find it especially tragic that violence has broken out in the land of Christ's birth during the Christmas season. Despite the fact that neither of the two parties follows the Christian liturgical calendar, many of us still cling to a vague sense that Christmas should be a time when all combatants-Christian or otherwise-lay down their arms, if only briefly.It's tempting to see such sentiments as a relatively harmless form of nostalgia, a recollection of a more self-confident age when, thanks to the Jesuits and the British Empire, we could think of Christianity as an enterprise on which the sun never set. Such nostalgia, though, sits uneasily in a culture where store clerks are now so aware of the diversity of our holiday traditions that they no longer seem to know what to say after they hand us our change.More to the point, the idea that Christmas is a "season of peace" is a form of sentimentalism that robs the Incarnation of its eschatological force. On Sunday, we heard Simeon prophesy that the Christ child was "destined for the fall and rise of many in Israel and to be a sign that will be contradicted" (Lk 2:34). Soon we will hear that He and his parents are forced to flee their home while others are slaughtered in His place (Mt 2:16). The feast days immediately following Christmas are the feasts of martyrs: St. Stephen, the Holy Innocents, and St. Thomas Becket.It should not surprise us that the Octave of Christmas is soaked in blood. As Frederick Douglas once observed, "power concedes nothing without a demand." We who believe that the Incarnation marks a turning point in the struggle to redeem the world also know that the present ruler of this world is not about to go quietly. Like the French living under Nazi occupation who witnessed D-Day, we know that something fundamental and decisive has happened and that our situation is transformed, but we also know that there is much fighting and, yes, dying left to do before the end.Our weapons in this fight will not be the weapons of the world. Against hatred, we bring love. Against missiles, guns, and improvised explosives we will bring prayer, fasting, and witness. Against historical grievance and the burden of memory, we bring forgiveness and reconciliation. Against division and polarization, we bring the worship that makes us One Body, which we offer for the life of the world.Christmas, rightly understood, is not meant to be a brief period of refuge from the evils of the world. It is a summons to take up the struggle against those evils. It is a call to gird our loins and offer prayers to the One who "trains my hands for war and my fingers for battle" (Ps 144:1). The Messiah has come! Nothing will ever be the same again.