Old Testament Isaiah 7:10-17
Faith that Tests God
“Lord, if you would just show me a sign.” How many of us have been at that place in our lives where out of indecision or frustration or uncertainty we offer up this prayer, that if only God would reach down and make something tangible happen then for sure things would be better. If only we could know God’s will with certainty! At a point of inflection, that moment of going down one path or another, we long for God for reach into our lives and give sureness and clarity out of confusion and fear. So let us consider King Ahaz who appears in our Old Testament reading this morning from Isaiah chapter ten. For King Ahaz is offered the very thing that any of us would jump at, given the chance. Isaiah comes to him with these words: “11 “Ask a sign of the Lord your God; let it be deep as Sheol or high as heaven.”1 Ask! Anything you want, just ask, and the Lord will show it to you.
We conclude our survey of Isaiah’s prophecies for Advent this morning with this well known passage that concerns the events we look forward to on Tuesday night and Wednesday morning this week. “14 Therefore the Lord himself will give you a sign. Behold, the virgin shall conceive and bear a son, and shall call his name Immanuel.2” The words we hear this morning were spoken 700 years before the Nativity of our Lord, but these Words point us directly to that event. And they point us to what we must believe and know about the miraculous birth in Bethlehem.
Why does Isaiah bring this message to the king? To answer this question you must know some of the context, some of the history around just what is happening. The prophecies of the Old Testament do not exist in a vacuum. They involve real people and real places and real events, so we should know something about them to help us understand what God wants us to know about his Word today.
So here’s the situation: King Ahaz is in the line of kings from David. He has control over the southern kingdom, which is called Judah, where Jerusalem is, because the kingdom which was united under David is now divided again. And now there are storm clouds on the horizon in the form of the northern tribes of Israel who are in cahoots with Syria, and want to invade the territory of Ahaz because he won’t join up with them to create an alliance. It’s all politics and intrigue. In the first part of chapter ten we hear that “the heart of Ahaz and the heart of his people shook as the trees of the forest shake before the wind”3 because of this threat. He’s scared. But what you also need to know to understand Isaiah’s prophecy is the reason why Ahaz is in this position in the first place. The reason is that there is a superpower knocking on the door. The superpower is called Assyria. Ahaz thinks the best solution to save his own skin and keep in power is to get in cahoots with Assyria, to enter into some kind of treaty or covenant with them in the hope that they will leave him alone and go after the other kings who causing all the problems.
Sounds okay, right? What’s the problem? Politicians will generally do whatever is expedient to keep in office, they will say and do whatever is necessary. You don’t need to be a cynic to recognize that. But here’s the problem with Ahaz: the agreement with Assyria comes with a huge cost. We don’t hear about this in Isaiah’s prophecy but the history of 2 Kings tells us that Ahaz was required to worship their gods in order to appease them and obtain their help. He has abandoned faith in the one true God of Israel because of his short-sightedness. This is a terrible thing. It will not work for him the way he expects and hopes.
So now back to Isaiah. The Lord tells the prophet to go out to Ahaz, to give him words of assurance in the hope that he will not turn his back on God and worship the false Gods of Assyria. He does this two times. The second time, God amps up the message. “Ask a sign of the Lord your God; let it be deep as Sheol or high as heaven.”4 He is putting everything into this appeal. It’s like he is saying to Ahaz, if you don’t want to believe in promises and threats then at least believe because of a sign. Choose whatever sign you want.
This is the God who has bound himself to Israel, who longs to gather his people to himself in order that he may show them mercy and forgive their sins. God is not the possession of the prophets and priests, but he is made known to Ahaz directly by his Word. Ahaz comes down from the house of David, with whom God made a holy covenant. Now we know what’s going on. God is merciful and gracious, even though Ahaz has turned his back on God. God offers Ahaz anything he wants, just say the word, and you’ll have it! Who could pass that up? Well, Ahaz does. For he is now stubborn in his unbelief. It is all in vain. He has concluded that his only hope to the problem at hand is this alliance with a pagan nation. And now to the sins of unrepentance and unbelief he throws in blasphemy for good measure. “I will not ask, and I will not put the Lord to the test.”5 So lets get this straight: the guy who has abandoned the One True God for the false gods of an apostate nation now quotes the scriptures back at God? No, this is not a statement of pious faith, but rather one of hypocritical self-righteousness. He has alienated himself and his house from God.
But if Ahaz won’t ask for a sign, God will provide one anyway. If God’s people reject him and remain in their stubborn unbelief, God will show compassion and mercy. “The virgin shall conceive and bear a son, and shall call his name Immanuel.”6 The sign is given to offer assurance and confirmation that his promises are sure and true. This sign will be a miracle from heaven. The sign is a baby, wrapped in swaddling clothes, lying in a manger. A baby born of a Virgin, a miracle, just like Isaiah foretold.
The shepherds in the fields around Bethlehem are the first to hear the news, and they are told that they will find this sign, the cause of great rejoicing in heaven and on earth. Christ the Lord is he who Isaiah speaks of, the Word made flesh. No one else fits, no one else is called “God is with us.” Through the prophetic spirit God announced beforehand these things which are unimaginable and believed to be impossible for human beings would take place, in order that when it occurred it would be believed and received by faith because it had been promised. The prophecy of Isaiah is like a keyhole, and the only key that fits these words is the person of the Son of God who comes to us in the flesh. He has come to take away our sins, He has come to go to that hill outside Jerusalem in order to atone for our iniquities.
The sign is there, for everyone to see. Yet the evidence is not enough. Many will reject the promise, just like Ahaz. The signs that God gives us provide the grace and mercy that we need, they offer the forgiveness of sins and eternal life. But they do so where faith is unmistakably present. The Child in the manger is a sign unto to those who believe, who have faith in God’s Word that has been fulfilled. We now have the signs of the sacraments, what Luthers says are visible signs of divine intent. Holy Baptism brings entrance into the kingdom of God where and when faith is present. The body and blood of Christ that we receive in the Sacrament of the Altar is given to both believer and unbeliever alike, but only the one who has faith in these words, “this is my body, this is my blood,” receives the benefits Christ has to offer.
Ask for a sign, put God to the test, says Isaiah. Well, in the Old Testament this is usually not a good idea. The people journeyed through the Sinai grumbling as they went along and Moses said they were testing God. They were trying his patience. To test God is an expression of doubt, unbelief, and disobedience. Except when it is not. Except when God himself says, “go ahead. Put me to the test. See what happens. See that my Word is true. See that my promises are true.” And that’s what happens to Ahaz. It is no sin to test God when his very Word invites the testing.
This is what the sign of the baby in the manger means for us. God has spoken once and for all in the incarnate Word Jesus Christ. He has given us this promise, and by faith we grasp hold of that promise and never let go. This is the message of the angels which is proclaimed at Jesus’ birth. Immanuel has come, God is with us. The promisedsign is what sets the shepherds in motion. Let’s go see! Let’s put this message of God to the test! And sure enough, God is true to his Word. They found Him right where the angel said He would be, Christ was right there, for them. Today you can find Him right where Christ Himself says He will be, for us. Right here in the Divine Service, in the preaching of His Word and in His very Body and Blood. He is here to bring His good gifts of grace and mercy by faith. This is the faith that rightly tests God because it comes from His Word, this is the faith that believes in Christ and leads toward service to God and one another. This is God’s will for you, that he gave his only Begotten Son that whoever believes in Him would not die but have eternal life. So put God’s Word to the test. The signs are given to us for this faith, to strengthen and preserve it until we are brought safely into the bosom of our Lord for all eternity.
1 Is 7:11.
2 Is 7:14.
3 Is 7:2.
4 Is 7:11.
5 Is 7:12–13.
6 Is 7:14.