If you want to climb a mountain, you would not simply start walking down up a trail. No, before you scale Mount Everest, it might be a good idea to sit down and get a bird’s eye view of the mountain, see where it is steep and where it requires more attention. You may also try to look at pictures of the peak, so you know what to expect. Another important step along the way is to follow those who have scaled the mountain before you and follow in their footsteps if they were successful. That might make things easier for you.
The same applies to studying books of the Bible, especially towering “Mt. Everests” like Isaiah. If you start reading the book without knowing the big picture, you will find yourself lost midway through. I know because that happened to me the first time I read Isaiah. I didn’t know which part of the Old Testament I was reading because all the prophets sounded alike. That led me to think that Isaiah was unnecessarily longwinded at best and indiscriminately erratic at worst. I needed a map to the book to see the beginning, middle, and end in one place, and a guide to its historical circumstances. I needed the big picture. And that is what I intend to give you in this article, an overview of this monumental book of the Bible, Isaiah.
Unlike some other books of the Old Testament, Isaiah is easy to outline because it mirrors the Bible itself. Two major sections make up all 66 chapters. Isaiah 1-39 constitutes the first part of the book and Isaiah 40-66 the second part. Many commentators have observed how the first 39 chapters focus on judgment and the last 27 chapters on salvation. However, that is a bit of an oversimplification because judgment and salvation are interspersed in both sections.
There is a more helpful way to think about the two divisions. Alec Motyer, who wrote an excellent commentary on Isaiah, labels the first 39 chapters, “The Book of the King,” and the last 27 chapters, “The Book of the Servant.” The first part shows Jesus to be the Davidic King who will come to reign in righteousness whereas the second part shows Jesus to be the Servant of Yahweh who would come to ransom His people and justify them in His righteousness. With that as the larger structure, you can see how the smaller parts fit into the whole below:
SECTION 1: Book of the King (1-39)
a. The Lawsuit of the King (1:1-5:30)
b. The Vision of the King (6:1-13)
c. Trusting in the King (7:1-12:6)
d. The King of the Nations (13:1-27:13)
e. The King in His Beauty (28:1-35:10)
f. The Only Perfect King (36:1-39:8)
SECTION 2: Book of the Servant (40-66)
a. The God Who Deserves Service (40:1-48:22)
b. The God Who is the Servant (49:1-57:21)
c. The God Who Makes Servants (58:1-66:24) (Lawsuit is resolved)
As you can see from the outline, Isaiah envisions two main themes converging in the Messiah—kingship, and servanthood. There is a reason why that is significant, and it has to do with Isaiah’s historical background.
The prophet connects his book to 2 Kings 15-20 which records the history of Judah under the reign of Uzziah, Jotham, Ahaz, and Hezekiah (Isa 1:1). We find in the book of Kings an unending search for the ultimate King who would descend from David—one who does what is right in the eyes of the Lord, one who makes justice roll down like waters and righteousness like an ever-flowing stream. But if you are familiar with the story, the quest goes unfulfilled. King after king takes Judah spiraling down into exile.
So, while the book of Kings records the history of imperfect and feckless kings, Isaiah envisions the perfect King who also perfects His people. Isaiah’s King will not only rule with righteousness but also serve with utmost obedience and sanctifies His people for such obedience. This is where the idea of servanthood comes in. It is not enough to have the perfect King as long as we have a sinful people. They will bring destruction upon themselves and ultimately go into exile. For instance, Hezekiah and Josiah were better than most kings, but they could not stop the exile because they could not make the people obey the law. The King must also show them how to be servants and ultimately make them the kind of servants they ought to be in order to inherit the Kingdom. Isaiah shows that there is a perfect King, and He loves His people so much that He became a servant to make His people servants. And that is how Yahweh saves His people—through His King and Servant. That brings us to the meaning of Isaiah, “the salvation of Yahweh.” The thrice holy God will Himself condescend to take on the form of a servant and sacrifice Himself to sanctify His people unto a holy servitude. That sums up the salvation of Yahweh in the book of Isaiah and in Scripture itself. Here we begin to breathe the pure, thin air of the mountain peak.
When you inevitably get stuck in a passage and need help understanding what it means, you can (and should) always rely on those who have studied the book longer than you have. Here are a few such people and their books to help you along the way:
Grogan, Geoffrey W. “Isaiah.” In The Expositor’s Bible Commentary: Proverbs–Isaiah (Revised Edition), edited by Tremper Longman III, Garland David E. Vol. 6. Grand Rapids, MI: Zondervan, 2008.
Motyer, J. A. The Prophecy of Isaiah: An Introduction & Commentary. Downers Grove, IL: InterVarsity Press, 1996.
Oswalt, John N. The Book of Isaiah, Chapters 1–39. The New International Commentary on the Old Testament. Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1986.
________. The Book of Isaiah, Chapters 40–66. The New International Commentary on the Old Testament. Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1998.
Oswalt, John N. The Holy One of Israel. Studies in the Book of Isaiah. Cambridge, UK: James Clarke & Co., 2014.
House, Paul. Old Testament Theology. Downers Grove, IL: IVP Academic, 1998.