Hear Isaiah’s Advent Call!

They were all Advent preachers. From Moses to Malachi their messages were the same. Repent. Return. Believe. Yes, they delivered their messages in different ways, and at different times. But ultimately, they were the voices of God calling his people to turn away from their sins, return to him, and put their faith in his promises.

Then for nearly 400 years there were no Advent preachers. The Old Testament ended. Since God’s people weren’t listening to him, he stopped talking to them. Then one day a man dressed in strange clothes who ate strange things appeared. His message was the same. Repent. Return. Believe the good news that God has sent his Son on a salvation mission!

For our sermon this morning we are invited to hear a message from the Prophet Isaiah in his role as an Advent preacher. Actually, we hear three messages connected to three voices calling out in his prophecy. Today, may God the Holy Spirit enable each of us to:

“HEAR ISAIAH’S ADVENT CALL!”

I. A call to repent (vv. 3-8)

II. A call to believe (vv. 1-2)

III. A call to receive (vv. 9-11)

Isaiah has been called the evangelist of the Old Testament. In other words, he pointed people to Jesus perhaps more than any other prophet. Although he brought bad news to his people concerning God’s judgment on their sins. He also delivered good news about the Savior who would come and set them free from sin. He was a powerful Advent Preacher.

Before we jump into these verses from Isaiah 40, I want you to recall the structure of the whole book of Isaiah. The first thirty-nine chapters of Isaiah reveal God’s judgment on his people and his condemnation of their sins. Yes, there are some Gospel promises found in those chapters too but for the most part it would be fair to call the first part of Isaiah a Law message. God pointed out the sins his people were committing, and he promised them that punishment was coming! On the other hand, the last twenty-seven chapters of Isaiah declare a message of hope and comfort as they point ahead to the work of the Messiah. You may remember that is why some people have called Isaiah a “mini-Bible.” Over the years some have seen the 39 Books of the Old Testament and the 27 Books of the New Testament are mirrored in the structure of Isaiah’s prophecy. Obviously the verses we are considering come from the second half of Isaiah—the half most rich with the Gospel. Here the LORD comforted his people at Isaiah’s time. And in these verses he will comfort us as we hear Isaiah’ Advent call.

I.

Isaiah used to powerful images to illustrate how God’s people would repent and return to the LORD their God. We jump to verse 3 of Isaiah 40. “3 A voice of one calling: “In the wilderness prepare the way for the LORD; make straight in the desert a highway for our God. 4 Every valley shall be raised up, every mountain and hill made low; the rough ground shall become level, the rugged places a plain. 5 And the glory of the LORD will be revealed, and all people will see it together. For the mouth of the LORD has spoken.” We heard verse 3 quoted by Mark in our Gospel Lesson for this Sunday. Isaiah’s prophecy was most directly fulfilled by John the Baptist. And we know from the Gospels in the New Testament of the Bible that some of God’s people did repent when they heard John’s Advent call.

Perhaps you know the story of John’s birth. His father and mother, Zechariah and Elizabeth, were well along in years. But God chose them to be the parents of a very special child. Do you remember what the angel Gabriel said to Zechariah about John? “He will be a joy and delight to you, and many will rejoice because of his birth, for he will be great in the sight of the Lord.” Then Gabriel went on to describe John’s mission. “Many of the people of Israel will he bring back to the Lord their God. And he will go on before the Lord, in the spirit and power of Elijah, to turn the hearts of the fathers to their children and the disobedient to the wisdom of the righteous -- to make ready a people prepared for the Lord.” (Luke 1:11-17). You may also remember that Zechariah didn’t whole-heartedly accept Gabriel’s message that he would be the father of a special child. As a reminder of his doubt and as a call to repentance God afflicted Zechariah with nine months of laryngitis. He was unable to speak until his son John was born. Then he accepted John’s mission. He said of his little baby boy, “And you, my child, will be called a prophet of the Most High; for you will go on before the Lord to prepare the way for him, to give his people the knowledge of salvation through the forgiveness of their sins, because of the tender mercy of our God, by which the rising sun will come to us from heaven to shine on those living in darkness and in the shadow of death, to guide our feet into the path of peace.” (Luke 1:76-79) Zechariah and Elizabeth and all the people in Israel had one reason to listen to John as an Advent preacher. He came with a call to repent.