In the original version of the carol, the comma comes after "merry", not after "you".
So anyone dropping by: God rest you merry, whoever you are.
Think about what it means that God would incarnate in a woman's womb and as a fragile infant. As a toddler. As a six year old. As a teenager. As a young man of 21 with his whole life ahead of him . . .
I have already put three Christmas stories on the blog this December - The Wild Geese of Bethlehem; O Holy Night; and The Body God - so it is only sufficient for me to say, this Christmas Eve: He comes to make his blessings known far as the curse is found.
And God rest you merry this whole and holy season.