John the Baptist is the preacher of Advent par excellence. He stands on the threshold between the Old and New Testaments with one foot in the Old Testament and the other in the New. The prologue of Mark’s Gospel (Mark 1:1-8/Advent II) provides a compact introduction to this wilderness preacher moving quickly to the One who comes after John. Matthew and Luke provide more extensive coverage of John the Baptist. Luther points out that the Gospel according to John is much more terse omitting the details of John the Baptist’s unusual birth.* The fourth evangelist simply introduces him as a man sent from God whose name was John (John 1:6). The Fourth Gospel is more interested in John’s mission as he outlines it in John 1:6-8, 19-28 (Advent III). John is not the Light; he is the servant sent to bear witness to the light.

Luther understands the office of John as that of preacher who announces the end of the old and the beginning of the new: “The beginning of the eternal kingdom of Christ and the New Testament are coincident with the time of John the Baptist. And simultaneously the regime of Moses, of the prophets, the priests and the Levites are terminated” (Luther’s Works, American edition (AE) 22:38). Stern though his preaching is as he denounces sin and proclaims a repentance that is a fierce call to turn away from the darkness that is characteristic of human existence from the time our first parents grabbed for God apart from His promise, John has yet another assignment. He is the great preacher of consolation for He bears witness to the light.

The hymnist, Johann Gottfried Olearius, puts it this way:

When all the world was cursed by Moses’ condemnation,
Saint John the Baptist came with words of consolation.
With true forerunner’s zeal the greater One he named,
And Him, as yet unknown, as Savior he proclaimed. (Lutheran Service Book 346:1)

John is not a new Moses coming with yet more wrath and condemnation. John knows God’s holy Law is not the Light of the world. That place is reserved for Jesus. He is the Light proclaimed by John in the darkness just before the dawn.

John knows God’s holy Law is not the Light of the world. That place is reserved for Jesus.

John, like every other preacher in Christian history, is not the light. He does not invite his hearers to bask in his glory, be enlightened with his novel principles, or imitate his austere life.

“John is a servant and not the Lord Himself. He is the teacher and guide to the true Light, but not the Light Itself. He administers a more exalted and glorious office than the prophets did; for John did not prophesy, as they did, that Lord will appear sooner or later. No, he points his finger at Him who is already present and says: “Behold, that is He.’” (AE 22:64)

John is more than a prophet in the long success of prophets who have been sent by God from the Fall onward. John is the final prophet, “the messenger” (Malachi 3:1-4; Mark 1:2), who is sent to prepare the way of the Messiah. Now in his words, the many and various forms of prophetic speech come into concentrated focus. As John 1:29 says: “Behold the Lamb of God who takes away the sin of the world!”

John is sent into a world darkened by sin and in the perpetual shadow of death. The whole of his life and ministry is spent directing people away from himself saying, “I am not the Christ” (John 1:20). John knew his place. He was not the light but a witness to the Light of the world. Luther puts it like this:

“In brief, he is not the Light; he is a servant and witness to Christ. His duty is to preach how and in whom I am to believe. He is a witness to the Light. Through his office he is instrumental in our becoming children of this Light. Because of this he shines and serves as a valuable light. However, in comparison with Christ he is nothing but darkness. The relationship is like that of the moon and the stars. They gleam by night but not by day; they count for naught without the sun; none of them can usher in the day. The saints, with their praiseworthy lives, shine similarly; and yet by themselves they can bring no one to salvation. John is not the Light, although he leads many to the Light. But with respect to his office John the Baptist is a great man, and for its sake we laud and honor him.” (AE 22:66)

John’s greatness is found solely in the One to whom he bears witness. Without Christ Jesus, John would be one of many preachers of apocalyptic woes. But in the economy of God, he is the messenger sent to prepare the Messiah’s way and the coming of His royal reign. John the Baptist will fade into the background but the Light he pointed to in the darkness will never grow dim and shines even now. “The light shines in the darkness, and the darkness has not overcome it” (John 1:5).

* For a helpful overview of Luther’s understanding of John the Baptist, see Dennis Ngien, Luther’s Theology of the Cross: Christ in Luther’s Sermons on John (Eugene: Cascade Books, 2018), 26-29.