Karl Barth was one of the most influential theologians of the twentieth century. The crux of his theology, around which everything he wrote revolved, is the claim that Jesus Christ is the unique and full revelation of God in history, the fulfillment of scripture, the true Word of God. This Christ-centered theology seems to have found its inspiration, or at least its kindred spirit, in the copy of a painting done by Matthias Grünewald that hung behind Barth’s desk for more than fifty years.
The artist Matthias Grünewald was a contemporary of Martin Luther, and his masterpiece the Isenheim altarpiece was completed around the year 1515. It is a complex system of panels intended for the altar at the monastery in Isenheim, Germany where monks ran a hospital devoted to the sick and dying. The copy that hung above Barth’s desk was that of the crucifixion scene in Grünewald’s masterpiece. It’s a realistic, grim representation of the crucifixion. In the center, the tortured and contorted body of Christ hangs on the cross. To one side of the cross Grünewald depicts the trio of Mary Magdalene, Mary the mother of Jesus, and the disciple John (into whose care Jesus placed his mother Mary). On the other side of the crucified Christ we find John the Baptist—Bible in his left hand, while the index finger of his right hand points to Christ hanging on the cross. At his feet we see a lamb carrying a cross. One foot of John the Baptist points toward us who gaze upon this painting, while the other points to Jesus; it’s as if even through his stance, John the Baptist draws us in and then turns our attention to the one on the cross. John’s size in the painting is smaller than that of Christ, with these words of scripture found behind John’s arm: “He must increase, but I must decrease.” This is the John the Baptist we find in the fourth gospel, the gospel of John.
It’s a different image of John the Baptist than what we see in Matthew, Mark, and Luke. There we find John the Baptizer, baptizing hundreds of people in the Jordan River. Or John the Prophet, clothed with camel hair, a leather belt around his waist, eating locusts and wild honey—a throwback to the days of the great prophet Elijah. Or in Luke John the Seeker, who sends two of his disciples to Jesus to ask: “Are you the one to come, or are we to wait for another?” These strong character depictions of John the Baptist give way in the fourth gospel to a John the Baptist who is a road sign. This is a John the Baptist who simply stands and points to Christ.
We see it in today’s gospel reading: “There was a man sent from God, whose name was John. He came as a witness to testify to the light, so that all might believe through him. He himself was not the light, but came to testify to the light.” And as John testifies to the light, every inquiry that comes his way from the priests and Levites from Jerusalem gets redirected to the one who is coming after him. I am not the Messiah, John says, and I’m not Elijah or the prophet. Instead, he says, “I am the voice of one crying out in the wilderness, ‘Make straight the way of the Lord.’” In the gospel of John, this John, John the Baptist, is primarily a voice that heralds the coming of one much greater than himself. It’s a John the Baptist that, like that of Grünewald’s painting, points away from himself. As Karl Barth once wrote of both the John the Baptist in scripture and that found in Grünewald’s painting: “John the Baptist is no independent figure. He belongs entirely to Christ…. He is only there to collect and give back the light that falls upon him by the one and only Christ.”
This image of John the Baptist serves as what may be a much needed corrective to the way we often function in the Advent season. So often at this time of year our minds are going ninety miles an hours with all the things we need to do to get ready for Christmas—gifts, parties, cards, a million different details taking up every spare corner of our brain. And when we do slow down enough to think, slow down enough to sit with this season of waiting, we tend to direct our thoughts inward in the process of soul-searching and analysis.
Now I realize that I have said previously that that’s what we should do in the season of Advent, take stock of our lives and the many ways we still live as if Christ had never come, and that’s true. But John the Baptist reminds us that even as we do this work of self-reflection, we do so ever keeping before us the coming of One who is greater than us all. We do so as witnesses to the event for which we wait, always pointing forward to that baby lying in a manger. As much as Advent calls us to go deep inside ourselves, it also calls us outward and beyond ourselves, to be witnesses to the light that breaks into the darkness of this world.
The verses that follow today’s gospel reading speak of John the Baptist’s reaction the next day upon seeing Jesus walk toward him. John declares: “Here is the Lamb of God who takes away the sin of the world.” Here is the Lamb of God…. It’s John once again testifying to the light. And this declaration of Christ’s presence, of light in the midst of darkness, isn’t a role that only John the Baptist plays. Barth writes: “This is what the Fourth Evangelist wanted to say about this John, and therefore about another John, and therefore quite unmistakably about every ‘John.’” In other words, just like John the Baptist who stands pointing to Christ, and just like John the writer of this fourth gospel who writes about all the signs that point to Christ as the Messiah, so too are we to bear witness to Christ, to stand in this season of Advent and direct the gazes of others towards the one for whom we wait, the one who comes to us over and over again.
We’re to stand in this world and bear witness to light in the midst of darkness, naming it each and every time we find it, saying: “Here is the Lamb of God.” Reconciliation takes place after decades of estrangement—it’s like a ray of sunshine penetrating the darkness, “Here is the Lamb of God.” Another meal is served on a Saturday at Neighbors Table—“Here is the Lamb of God.” An international aid worker gathers up in her arms a severely malnourished infant with all the tenderness of a parent towards his or her own child—“Behold the Lamb of God.” The John the Baptist we find in the fourth gospel, the John the Baptist of the Isenheim altarpiece, reminds us that during Advent, as we wait for the coming of Christ, we’re also to bear witness to the light that is breaking into the world even now, to the places where we see and can name the presence of Christ among us. So one more question to add to our Advent reflections: How do our lives point beyond us to the one for whom we wait? How do our lives testify to the light?
 From Karl Barth’s The Great Promise, as quoted in Feasting on the Word, Year B, Volume 1, Louisville: Westminster John Knox, 2008, page 68.