Zechariah couldn't say a word for his wife's whole pregnancy. His voice came back the day their son was named, and he used it to praise God, then to name what was coming, the tender mercy of our God. He said it months before the shepherds heard anything, while the world still looked exactly as it had the day before.
Not everyone arrives in December with much Christmas in them. These four Sundays stay with the harder parts of the story. A family tree with scandal in it. A long silence. Witnesses nobody would have picked. A shadow across the manger. Mercy runs through all four.