Churches usually have soporific slogans on their notice board and Christmas letterbox flyers.
As an attempt to lift the game, here are a few more useful slogans:
Christmas! Time to stop worshiping yourself
That time of year when your worldview walks the plank
God's gift: life in him. Better than your crummy gifts.
Christ came bringing light. Your choice if you want to stay in the dark.
Christmas: time for your annual gift to charity to feel good about yourself...again.