Children of Abraham by Faith

This sermon was preached for the Second Sunday of Advent, on Sunday, December 7, 2025.

Grace, mercy, and peace be with all of you from God our Father and from our Lord and Savior Jesus Christ. Amen.

John the Baptist was quite a character, wasn't he? The first word out of his mouth is repent. He's not nice about it. He says, "Repent, the kingdom of heaven has come near." Isaiah, the voice of one crying out in the wilderness, says "Prepare the way of the Lord, make his paths straight."

If you've ever been in an area that can be properly called "wilderness," you know that what he is talking about here is a bleak and barren place.

Have you ever tried to shout in the wilderness? Ever tried to just see how far your voice will carry if you're looking for an out in the middle of an open stretch of desert? You can shout at the top of your lungs, but nothing comes back. It's actually quite eerie because there's nothing there. Sand and rocks, maybe a little scrub brush here and there, or a cactus. The only thing that's going to hear you is the wind.

The wilderness is a place that's bleak. It's a place that is foreboding. It is not a place of life. (Nowadays, we know that that's not really the case. The desert is actually a fascinating place. If you go out in the desert, you can find all kinds of life if you know where to look. But it's not a hospitable place.) It's a difficult place to make your life.

John's Unique Calling

This is where John the Baptist goes. This is the one who in the belly of Elizabeth of the Blessed Virgin Mary and leaps for joy at the sound of the mother of his Lord In the womb, he's already testifying to Christ.

Now it appears — some would say he's taken a Nazarite vow, a vow never to cut his hair. That may be true, but he has become somebody who is set aside for a religious purpose, and God is using him in a unique and unusual way.

Because he's out in the wilderness here, he's not dressed as ordinary people would be dressed in those days. He is wearing the most uncomfortable clothes that the people of the ancient Near East could imagine: He's wearing camel's hair for his clothing.

I don't know if you've ever been around a camel. They don't smell especially great, but they also have very coarse fur, and that hair is very difficult to turn into anything. It makes you wonder, how on earth is he even able to get yarn out of that to make clothes?

And he's also eating strange food. What is he subsisting on? Nothing but the finest locusts and wild honey. (Maybe this idea of eating bugs is an ancient one instead of a modern one.)

This man eating locusts and wild honey is living off the land, subsisting on what God provides and nothing else, entirely in God's care, and wearing some of the most unimaginably itchy clothing you could possibly think of. He's out in the wilderness, and he begins to preach:

You see, his purpose is not to be the center of attention. His purpose is not to be the one to whom everybody comes. His purpose is to be a signpost, to point to the one coming after him.

He's quick to do that. He commands them, "Repent, for the kingdom of heaven has come near," and already out of the first sentence out of John's mouth, his words are of Christ, for he's speaking of the kingdom of heaven coming in the form of this man who will rule the Gentiles, the man about whom the prophet Isaiah prophesied.

The one about whom St. Paul writes, "Therefore I will confess you among the Gentiles and sing praises to your name. The root of Jesse shall come," he's quoting Isaiah, "the one who rises to rule the Gentiles. In him the Gentiles shall hope."

People have been looking for a Messiah in that region for hundreds of years, at least 600, probably longer. The Messianic hope is one that goes back to Abraham, for he recognized that it was necessary that he be saved, and it was necessary that he be saved by sacrifice.

God himself provided the sacrificial ram for Abraham in place of his only begotten son, so that Isaac might be replaced with this ram, an animal's blood accepted in the place of human life.

Now we come to the ultimate of sacrifices, where not Father Abraham, but our Father God himself, sends his Son to live among us, to be the blessed Lamb of God who takes away the sin of the world.

But before he makes his appearance, John has his part to play.

The People's Response

People come out in droves. You'd come out in droves too if you saw a guy who only ate bugs and wild honey and camel hair clothing! You would be excited to see that. You'd say, that's very strange. I would like to see that with my own eyes.

He's got a religious message he's sharing. I guarantee everybody here in this room would say, man, that's different. That's interesting. I want to go see that. I want to know what this man is all about.

Some of you would be going to genuinely hear what he has to say. Some of you would be going there just for the spectacle of it. But everybody would be interested in it.

He's begun to preach repentance, because the kingdom of heaven has come near. That's a message you don't hear every day. "The kingdom of heaven has come near" is a different kind of thing than "Repent, because God is mad, and he demands that you do better."

He's not saying repent and get good. He's saying repent because the kingdom of heaven is near you. It is coming to you. It is not any longer about your ascent into the heavens or yourself, the prize of righteousness. But the kingdom of heaven has come to you. It has come to you to bring you the righteousness of God where you could not ascend the ladder of righteousness yourself.

Confronting the Religious Leaders

That's not all he has to say. Yes, people come. They hear the message. They see the strange man saying strange things, and they are baptized into repentance.

But then others come, people who are more like me, than you, frankly. Pharisees and Sadducees, religious leaders. John is not particularly thrilled. He calls them, "You brood of vipers!" Let me translate that for you. This is the Ted Carnahan translation:

"You son of a snake! Who warned you to flee from the wrath to come?"

In other words, John was saying, "I was kind of looking forward to seeing you burned up with the other trash."

He's not treating them kindly. But the reason he's not treating them kindly is not because they are unable to repent, but just because they've become so stubborn and stiff-necked and unaware of their own sin that they believe that they are righteous in God's eyes just by virtue of who their ancestor was.

He immediately jumps to this question. "Do not presume to say to yourselves, we have Abraham as our ancestor. For I tell you, God is able from these stones to raise up children to Abraham."

Here, John is doing something more than just challenging the religious underpinnings of the Pharisees and the Sadducees in their own self-satisfied self-righteousness. He is calling them to recognize that God is doing something in Abraham that is more than just establishing a righteous ancestor for the people, the natural people of Israel, the Hebrew people. He is establishing Abraham as the father of all of us who trust in God by faith.

God is able from these stones, from rocks on the ground in this wilderness place, to raise up children of Abraham. People who are children of Abraham not by blood, but by confession. Because what children of Abraham do is they confess. They believe.

When he says later that he is preparing the way for one who will come whose sandal he is not worthy to untie, who will baptize you not just with water for repentance, but with a new baptism, the baptism of Jesus, that gives you the Holy Spirit that fills your heart with faith, he is saying this, here is how this man, Jesus, who is the Son of God, will come and raise you up as children of Abraham. Not because you were generated by the relations of a man and a woman that trace your ancestry back to some man in the ancient Near East a thousand plus years ago, but because you believe in the Promised One to Whom John is pointing.

If you would be a child of Abraham, don't put your trust in Abraham, but do what Abraham did and trust in the future fulfilled promise of God.

That future fulfilled promise of God, the kingdom of heaven which has come near, is here for you in this moment in the person of the one who is coming, John says, the man who is coming who is Jesus the Christ.

"I baptize you with water for repentance and the one who is more powerful than I is coming after me and he is so much better than I am, I'm not even worthy to carry his sandals. He will baptize you with the Holy Spirit and fire."

That baptism of the Holy Spirit, that Baptism in the triune name of God, marks those who have been so baptized as children of God and gives them the gift of the Holy Spirit and therefore gives them the gift of faith and makes it possible for us to do what John starts off saying to us in the beginning of our passage today.

Because if we're honest with ourselves, we're terrible at this repentance stuff. It's never a completed task for us. We're always sinning more and more and even when we try to be on our best behavior, the necessity of repentance always stands above us as a demand that we cannot reach.

But then, God reaches down to us and grasps us by Holy Baptism and holds us in his hands and gives us faith and repents for us, turns our hearts back to God in a way that we cannot accomplish on our own, fills us with his grace and his truth and sends us off into the world to proclaim the good things that God has done.

God's Grace Through Christ

It's easy to read John the Baptist as a man who is angry, judgmental, and full of wrath. But actually what he's doing here is he's showing you God's amazing grace!

Because He has stooped down to his people, both Jew and Gentile. He has rescued all of us and grafted us Gentiles into the kingdom of his son, Israel, redeeming us by the blood of Jesus Christ and making that blood effective to us, not by the sacrifices made by Abraham long ago on the Mount Moriah, nor by the blood offered by priests in the temple, but by the blood offered by our great high priest, our Lord Jesus Christ, who cleanses us by his blood on the cross, who in dying has destroyed death and in rising has brought us to new and eternal life so that we can be well prepared for his second coming.

May you trust the Lord Jesus in this time of preparation and waiting, not by your own righteousness or even by your own repentance, but by the repentance which God gives you as a pure gift by his Spirit. May you know the love and grace of God which surrounds you in this season of preparation. May you trust in the one who calls you to better and higher things.

And may the peace of God which surpasses all understanding keep your hearts and minds strong in Christ Jesus our Lord to life everlasting. Amen.