“He Shall Reign Forever”: Isaiah 9 and Christ’s Eternal Kingdom

History records the rise and fall of countless principalities and empires. Take Winston Churchill as a somewhat recent example. During the Second World War, the prime minister enjoyed 83 percent approval of the people. By July of 1945, two months after the war ended, he and his Conservative Party experienced a crushing defeat. Swept out of power, their reign was over.

This event reflects a key feature of the story of human history. “Earth’s proud empires,” penned the hymn writer, “pass away.” But the Bible presents us with a different picture. Isaiah 9 describes a kingdom that will last forever. It is no ordinary kingdom, and on the throne is no ordinary King:

Of the increase of his government and of peace
 there will be no end,
on the throne of David and over his kingdom,
 to establish it and to uphold it
with justice and with righteousness
 from this time forth and forevermore.
The zeal of the LORD of hosts will do this. (Isa. 9:7)

The Context for Isaiah 9

In its immediate context, Isaiah 9 speaks of a child to be born, revealed in the New Testament as Jesus of Nazareth. He is the true King and Shepherd of Israel, in whom is to be found the peace our world needs. 

More broadly, we also know that the book of Isaiah as a whole has a context. The prophecy of chapter 9 comes on the heels of the promises of God that have preceded it.

Centuries earlier, at the end of the period of the judges, Israel had declined into moral chaos. The book of Judges itself concludes, “In those days there was no king in Israel. Everyone did what was right in his own eyes” (21:25). As a result, the people had decided appointing a king would be the solution to their dysfunction. With both reluctance and graciousness, God gave them a king—but kings came and kings went, as monarchs inevitably do, each failing in one degree or another.

Jesus is the true King and Shepherd of Israel, in whom we find the peace our world needs.

By the end of the Old Testament, we sense a longing for one who will sit on David’s throne as the true king. This longing, we understand, was fulfilled in the angelic pronouncement to Mary:

The angel said to her, “Do not be afraid, Mary, for you have found favor with God. And behold, you will conceive in your womb and bear a son, and you shall call his name Jesus. He will be great and will be called the Son of the Most High. And the Lord will give to him the throne of his father David, and he will reign over the house of Jacob forever, and of his kingdom there will be no end.” (Luke 1:29–33)

Unlike those before Him, this King would have no successor. Nobody would come after Him; no one would replace Him.

It’s this King, the Lord Jesus Christ, to whom Isaiah 9:7 points. And this verse outlines several qualities of God’s kingdom, defining for us what it is and what it is not.

A Boundless Kingdom

God’s kingdom, we learn, is unbounded, both geographically and temporally. Earthly kingdoms have boundaries. We need passports to move from country to country. Boundaries allow us to read history and say, “There was a time when there was a Roman Empire, a Greek Empire, a British Empire,” and so on. But not so with God’s kingdom.

The spiritual nature of the kingdom Christ proclaimed didn’t make sense to His contemporaries. Jesus told Pilate, “My kingdom is not of this world” (John 18:36), and to the Pharisees Jesus explained, “The kingdom of God is in the midst of you” (Luke 17:21). In other words, where the King is, there the kingdom is as well.

As Christians, it’s crucial we grasp this aspect of the kingdom. Believers, Hebrews tells us, have come to Mount Zion already (12:22). As we live within our allotted national boundaries, we’re members ultimately of the invisible kingdom of God—a kingdom established by peace, framed by justice, and defined by righteousness.

Where Jesus is, there the kingdom of God is.

These realities reshape our priorities. How we answer the first question of the Heidelberg Catechism—“What is our only hope in life and death?”—matters a great deal more than where our children are educated or whether we’ve secured the borders of our nation. While the latter issues are important, the former is of greater importance for the Christian.

An Eternal and Universal Kingdom

Rather than being temporal or local, God’s kingdom is eternal and universal. The prophet Habakkuk tells us that much:

For the earth will be filled
 with the knowledge of the glory of the LORD,
 as the waters cover the sea” (2:14).

The growth of God’s kingdom isn’t a result of military, cultural, or political conquest, by which the kingdoms of this world often increase their dominion. Instead, this kingdom grows as the Gospel is proclaimed in the power of the Holy Spirit.

We shouldn’t equate this lack of physical force with weakness, though. Daniel, describing the coming of the kingdom, pictures it as a rule that “shall break in pieces all these kingdoms and bring them to an end” (2:44). So forceful is the divine kingdom that even today, it’s taking ground within nations opposed to its rule. In places like mainland China, sub-Saharan Africa, and South America, God’s kingdom is growing one renewed heart at a time.

A Powerful Kingdom

Isaiah 9:7 concludes with a word on the powerful working of the kingdom: It’s by “the zeal of the LORD of hosts” that God establishes His rule.

After the angel told Mary about the coming King and kingdom, the virgin asked, “How will this be …?” (Luke 1:34). It’s almost as if Isaiah anticipated this question on behalf of his initial readers. The events Isaiah describes and in which Mary participates wouldn’t transpire in an ordinary course of affairs. For all these things to take place, God, immeasurable in His power, had to be involved.

“The zeal of the LORD of hosts” is a significant biblical phrase. If we think along the lines of godly jealousy, we’re on the right track. It’s the picture of a concerned father for the purity of his daughters. It’s the jealousy of an oncologist for the eradication of the cancer he finds in his patients. This jealousy, this “zeal,” is entirely right and good.

We might say it this way: The blessings described in Isaiah 9 are tied exclusively to the one who sits on the throne. We cannot divorce the King from His kingdom.

In his beloved children’s book The Last Battle, C. S. Lewis lets the reader in on an exchange between Lucy and Aslan, king of Narnia:

Lucy said, “We’re so afraid of being sent away, Aslan. And you have sent us back into our own world so often.”

“No fear of that,” said Aslan. “Have you not guessed?”

Their hearts leaped and a wild hope rose within them.

… “Your father and mother and all of you are—as you used to call it in the Shadow-Lands—dead. The term is over: the holidays have begun. The dream is ended: this is the morning.”And as He spoke He no longer looked to them like a lion; but the things that began to happen after that were so great and beautiful that I cannot write them. And for us this is the end of all the stories, and we can most truly say that they all lived happily ever after. But for them it was only the beginning of the real story. All their life in this world and all their adventures in Narnia had only been the cover and the title page: now at last they were beginning Chapter One of the Great Story, which no one on earth has read: which goes on for ever: in which every chapter is better than the one before.

What is Lewis describing? The amazing spiritual reality described in 1 Corinthians 2:9: “No eye has seen” (it is invisible), “nor ear heard” (it is inaudible), “nor the heart of man imagined” (it is inconceivable), “what God has prepared for those who love him.”

We can trust the King and His kingdom completely.

Because God’s kingdom is eternal, we never have to leave. Because it’s universal, it’s for anyone who comes to Christ with humble faith. And because it’s powerful, we can enjoy assurance concerning our membership within its realm. We can trust in the King and His kingdom completely. 

This article was adapted from the sermon “He Shall Reign Forever” by Alistair Begg.