“The zeal of the LORD of Hosts will perform this.”

Today people are much more interested in whether things work than whether they are true. Such thinking (if we may call it that) enables them to be dismissive of the Christian message. But God not only tells the truth, he keeps it. What is more, he does exactly what he promises. Neither falsehood nor failure characterizes him; he can neither lie nor fail. That is the point of the above statement. God gets things done and what he does is the criterion of true success.

But not only the non-Christian world needs to be reminded of this. The church does, too. It did in Isaiah's day, and it does at the present time. That is why Isaiah repeated this declaration in chapters 9:7 and 37:32.

The first of these occurrences is well known because it is a part of a messianic prediction and is usually read in church services at Christmas-time. The second should be better known than it is because it relates to a moment of crisis for the Old Testament people of God.(1) The substantial connection between them contains a message not only for Isaiah’s people but also for the Christian church (2) because it was primarily for Christians that the Old Testament prophets spoke and wrote.(3)

Before examining each of these uses, some things about the words themselves should be pointed out. First, they have a definitive ring about them. When they are read publicly, there ought to be a noticeable pause after them and no onward rush to what follows. But secondly, they are not only emphatic, they are climactic. They tell us that what has just preceded them is going to be done and also how it cannot fail to come about. They have the same function as Gabriel’s declaration to Mary about the marvelous conception of the Son of God, “No word from God is void of power.”(4) Similarly, Isaiah’s expression “the zeal of the LORD of Hosts will perform this” guarantees the accomplishment of what he had just declared.
In order to examine Isaiah’s statement further, three simple questions will be posed, namely: What? How? Why?

What had been declared?

To understand what the LORD is declaring to do, we must look at the context of the two passages.
a) Isaiah 9:7 —Chapters 7-9 are set in Jerusalem, about 735 BC. The city is besieged by a coalition army from Syria and Ephraim that plans to replace Ahaz, the king of Judah, with a man named ben (son of) Tabeel. Isaiah brings a message of comfort from God and invites Ahaz to choose any sign as a guarantee of Jerusalem’s survival. However, Ahaz hypocritically refuses, veiling his unbelief by stating that he would not put the LORD to the test. So Isaiah announces a sign: the coming and reign of Immanuel who would rule over and for his people (7:14-9:6). That prediction of a more distant future guarantees survival in the short term – but only to those with faith.

b) Isaiah 37:32 — In this chapter, we are again in Jerusalem but it is 30 years later. This time Assyria is the foe, and a siege is imminent.(5) Hezekiah is now king, but he, unlike his father Ahaz, is a true believing son of David. He spreads before the LORD the letter that contains the taunts and threats of Sennacherib, the king of Assyria. The answer given to Hezekiah’s prayer is that there would be a remnant spared. The people of God would not be destroyed.

These two passages are linked because they concern the house and people of David and God’s commitment to them. Although there is a crisis in the house of David due to the sin of Ahaz (one of its unbelieving sons), the royal line and subjects will yet be preserved. This is because of the LORD’s covenant with David.(6) His messianic purpose will not be brought to a premature end by foes without or within, for a son of David is to come who will bring this purpose to such a fulfillment that it will have eternal consequences. He will build the LORD’s house, his temple-church.

And so no threat or foe thwarted the LORD’s plan. Just as had been the case with Pharaoh and Egypt, so it would be with Syria-Ephraim and Assyria, the foes of Isaiah’s day, and so it would be with the power of Babylon, of Persia, of Greece and of Rome – up until Immanuel was born. “The government [was] placed on his shoulder…and of his kingdom there shall be no end.”(7) The same story is recorded in the New Testament and continues up to the present time. An international church is now being gathered. It will survive until the crack of doom and the dawn of glory. The seed of the woman, of Abraham and of David has come. He died for sinners and rose again, vindicated by God and triumphant over sin and Satan. The gates of hell shall not prevail against the church.(8) “His kingdom is for ever.”

How is all this going to be done?

The accomplishment of what God predicts is beyond man’s power to effect. Not even the church brings it about. All is traced to God himself, who is described here in a particularly striking way.
First, he is referred to as “LORD of Hosts.” Isaiah uses this expression frequently in his prophecy as a synonym for “the Holy One of Israel.” God is the LORD who is the covenant redeemer of his people.(9)The hosts are the angelic beings who are at his command. This “name” indicates the ease with which God is able to accomplish every item in his saving purpose. It combines redemption and omnipotence, grace and power.

But here is the all-significant point. Although it would be more than enough for Isaiah to use the title “LORD of Hosts” to make his case, Isaiah adds something else. He also speaks of his zeal.
What is zeal? What does it mean with regard to God? The Hebrew term has the associations of “being red” and refers to a face that is flushed with roused emotion or expended energy. In other parts of the Old Testament, the Hebrew word is translated jealousy. God’s zeal and his jealousy are therefore one and the same. For human beings, jealousy is more often than not associated with envy – envy of what another has which we do not. But God has no one to be jealous of in that sense because there is no one like him. He has everything worth having. His jealousy or his zeal is his determination to remain all that he is, to retain all that he has and perform all that he says. He will neither give up because of his unworthy people nor give in to his (and their) implacable foes. He will exert himself strenuously to save – and will succeed! God is not half-hearted about the fulfillment of his redemptive purpose. When there is no one to deliver his people, he rises up as a warrior in his own saving cause to do it himself.(10) He “wraps himself with zeal as a mantle.”

We must not think that God is distant because he is supreme, nor casual because he is invincible, nor immobile because he is immutable. He could not be more involved – after all it was his well-beloved Son whom he sent into the world! His deity is dynamic, energetic, active and ardent!

Why is this being emphasized?

The repetition of this striking statement inculcates a right view of the true and living God, the God and Father of our Lord and Savior Jesus Christ. We need to absorb this view because all too often Christians regard God as if he were detached from and unconcerned about what is happening to his church and people. That is not the case. However, having a correct view of God is not the main purpose of this repeated statement.

Rather, it is to encourage faith in God’s willingness and ability to perform what he promises (11) – whatever the obstacles or the impossibilities. Although God is not manageable by us, he is dependable for us. These words challenge the professing Christian and the church. We are called to react in a way that is every bit as real as Ahaz and Hezekiah in their times of crisis.

Ahaz attempted to cloak his unbelief with a religious veneer. Refusing God’s offer of a visible promise to help him believe put the patience of God to the test.(12) This is the same as trusting in oneself or others. It is equivalent to signing one’s own death warrant. On the other hand, Hezekiah went into the LORD’s house to pray and asked the prophet to pray in the hope of obtaining an assurance from the LORD. That is what believing is – it is a helpless but confident leaning on the divine arm. Prayer is the opposite of both self-trust and self-love. It trusts the irrevocable intensity of God’s gracious omnipotence to save.

In a world where truth is devalued, the church and her message of “Jesus Christ and him crucified” is attacked. In adversity, how will we respond? Will it be in fear or faith, in unbelief or doubt? Is our name Ahaz or Hezekiah? Christians are not to be “faithless but believing,”(13) putting faith in God’s willingness and ability to do what he promises. “Let God be found true though every man be found a liar.”(14) Because Jesus is LORD, we should say with confidence, both to ourselves and to the world, “Has he not said and will he not do it?”(15)