I guess so far as MK is concerned, both today's JN & next Sunday's LK are marginal! Very! So here goes....
I notice that in the N.T. I use most, I've bracketed JN 1: 6-8 & 15 as interpolations, because they interrupt the flow of the incomparably magnificent & imaginative poetry of the traditional Christmas Gospel about The Word. Hinder the flow of what JN (is he the poet, or another?) is telling us about Jesus The God Event. It strikes me that something we oughtn't to do in our Advent 3 preaching is give JB, the Big Dipper, the stage that rightly belongs to the one he comes to 'introduce' to the world. Important role that he played, JB was not, repeat, not the Light, not the Word, not the God Event. Nor would he want to be an interruption to our preaching of the Word made flesh. We are to testify to Jesus, the Word, as JB does so faithfully.
JB makes his own role clear when questioned in the next section, 19-28. There are already enough things to distract us from Jesus as we head further into Advent & more & more hectically towards Christmas. Personal & commercial distractions ever more aggressively shoving aside Christmas & the Word of God at its heart. We can't stop the commercial juggernaut, but let's not get aboard & pander to it taking over Advent as well! (Three years ago when this cycle came around, someone showed me an advertisment for a 'Kylie Minogue Advent Calendar'! The mind still boggles after three years!)
JB is an example to us as he heads off his questioners & resists
getting bogged down about whether or not he's the Christ, Elijah, or the
Prophet. His questioners then give us a profitable preaching point: "Who
are you, then?......What do you say about yourself?"
JB knows who he is! "I am the voice of one crying out in the wilderness: Make straight the way of the Lord!" He has to work through what that means for him - we know what happens to him in the process - just as we must work through our answer to, "Who are you then? What do you say about yourself? in our own 'wildernesses'. JB's strength, & ours, lies in defining who we are & what we say about ourself first & foremost in terms of the One we're called to focus on. We can only do that in the power of the Spirit.
Truth is, not many question us these days as to what it is we're on about, in Advent or any other season of our Christian year. Largely they see us as irrelevant. Better at trying to tell them in in-house language they're not privy to than we are at showing them we know who we are, Whose we are, & what we are. Is what we say about ourselves as focused on Jesus as JB is?
JB's message to his questioners that there is 'one among them whom they do not know', is one that we need Spirit skills as well as water ones to pass on. There is a Jesus-like humility (itself a gift of the Spirit!) in the way JB speaks up here. A side of JB easy to overlook. But isn't it always easy to overlook humility? Rather than a downside, humility's is really God's down- sizing, to equip us to work as God works.