The Advent Proper Preface highlights the role of St. John the Baptist throughout this season, especially his preaching of repentance in anticipation of the coming of Christ Jesus; for St. John prepares His way by “proclaiming Him the promised Messiah, the very Lamb of God who takes away the sin of the world, and calling sinners to repentance that they might escape from the wrath to be revealed when He comes again in glory.” It is precisely by his preaching and baptism of repentance that St. John, the Forerunner, prepares the way of the Lord — not only historically but so also to this very day, and even to the close of the age — in the continued proclamation of his word and work in the life of the Church.
As the archangel Gabriel announced to Zachariah in advance, and as Jesus affirms in retrospect, St. John comes in the spirit and power of the Prophet Elijah to make ready the coming of the Christ (St. Luke 1:17; St. Matthew 17:11–17). That role is clarified in the Baptism of Our Lord (on the First Sunday after the Epiphany), when St. John, the priestly son, anoints the Lamb of God in preparation for His Sacrifice in order to fulfill all righteousness (St. Matthew 3:13–15; St. Luke 12:50; St. Mark 10:38). Thus, on Advent 3 (in the one-year lectionary, and in series A and C), Jesus not only responds to the question that John asks from Herod’s prison, but also instructs the crowds concerning John, that he is a prophet and more than a prophet (St. Matthew 11:2-15; St. Luke 7:18-35). His preaching is thus heard on Advent 4 (in the one-years series, Advent 3 in series B), pointing forward to the Christ who is coming after him, “that all might believe through him” (St. John 1:7). “Elijah” must come first (St. Matthew 17:10–12); then he must decrease, and Christ increase (St. John 3:30). Even while yet in his mother’s womb, St. John announces the coming of the Christ (St. Luke 1:41–44), as heard on Advent 4 (in series C, and in the alternative Gospel of the one-year lectionary). It should therefore come as no surprise that St. John the Baptist features prominently in a number of our traditional Advent hymns (LSB 344–347).
The Fourth Sunday in Advent does lean more toward the approaching celebration of the Nativity of Our Lord, especially in the three-year lectionary, which cycles through the announcements to St. Joseph and St. Mary and the Visitation of St. Mary to St. Elizabeth. The Visitation (St. Luke 1:39–56) also serves as the alternative Holy Gospel on Advent 4 in the one-year lectionary. As the Church is prepared for the coming of the Lord by the preaching of St. John the Baptist, so does she wait upon His coming with the Blessed Virgin Mary. These two figures, St. John the Baptist and St. Mary, the last and greatest of the prophets and the Mother of our Lord, are like the two sides of a hinge between Advent and Christmas, between the Old and New Testaments. And on the final Sunday before the Feast of the Nativity, there is an appropriate focus on St. Mary, the faithful handmaid of the Lord, who conceived and bore the Son of God within her womb. As she trusted the Word of God — and as that Word became flesh of her flesh and blood of her blood by the gracious and powerful working of the Holy Spirit — so does the Church hear and believe the same Word of God and give birth to the children of God by His Word and Holy Spirit through the Ministry of the Gospel.
Over the course of the Church Year, the festivals of the Annunciation (25 March), the Visitation (31 May or 2 June), the Nativity of St. John (24 June), and the Martyrdom of St. John (29 August) help to maintain the emphasis of Advent on the coming of the Lord in the flesh.
The Church savors all the weeks of Advent for what they are and offer, and she benefits from the catechesis of this season in the Word and promises of God. She waits and watches on the Lord in the patient confidence that her God and Father in heaven opens His hand to provide all that she needs, and that His Word becomes flesh and tabernacles with her in the fullness of time.