From the Word
15 When the angels went away from them into heaven, the shepherds said to one another, “Let us go over to Bethlehem and see this thing that has happened, which the Lord has made known to us.” 16 And they went with haste, and found Mary and Joseph, and the babe lying in a manger. 17 And when they saw it they made known the saying which had been told them concerning this child; 18 and all who heard it wondered at what the shepherds told them. 19 But Mary kept all these things, pondering them in her heart. 20 And the shepherds returned, glorifying and praising God for all they had heard and seen, as it had been told them.
Luke 2:15–20, RSV
Had not these shepherds believed the angel they would never have gone to Bethlehem, they would have done none of those things related of them in this gospel. One might say, I would gladly believe if an angel from heaven were to preach to me. But whoever does not receive the Word for its own sake will never receive it for the sake of the preacher, even if all the angels preached it to him. He who receives it because of the preacher does not believe in the Word, neither in God through the Word, but he believes the preacher and in the preacher. Hence the faith of such persons does not last long. But whoever believes the Word, does not care who the person is that speaks the Word, and neither will he honor the Word for the sake of the person; but on the contrary, he honors the person because of the Word, and always subordinates the person to the Word. If the preacher perishes, or even falls from the faith and preaches differently, he will forsake the person of the preacher rather than the Word of God.
All who believed Christ because of his person and his miracles fell from their faith when he was crucified. So it is in our day and so it has always been. The Word itself, without any regard to persons, must be enough for the heart; it must lay hold of man as if taken captive, so that he feels how true and right it is, even if the world, all the angels, all the princes of hell said differently, even if God himself spake otherwise; as he at times tempts his own elect and appears as if different from what he had before declared. So it was with Abraham when commanded to offer his son Isaac; with Jacob, while wrestling with the angel; with David, when persecuted by his son Absalom. This faith triumphs in life and death, and nothing is able to overthrow it; because it rests upon nothing but the Word without any regard whatever to persons. Such faith these shepherds possess; they cleave to the Word so strongly that they forget the angels who declared it to them. They do not say, Let us go and see what the angels made known to us, but what the Lord hath made known to us.
Martin Luther and John Sander, Devotional Readings from Luther’s Works for Every Day of the Year (Rock Island, IL: Augustana Book Concern, 1915), 456–457.