Chapters 56-66 are the third section of Isaiah’s book. You might remember way back when we began our study of Isaiah, I gave you the background of the Prophet and his book. I told you at that time that most critical scholars believe that the Book of Isaiah has multiple authors. Most accept a two-author scenario while others say even three authors can be detected.
Those who accept the two-author view contend that chapters 1-39 were indeed written before the Babylonian Exile by a Judean Prophet named Isaiah who lived in the early 7th century B.C. These same critical scholars, however, believe that chapters 40-66 were written by a Judean Priest after the Jews returned from their seventy-year exile. They refer to these chapters ad Deutero-Isaiah which simply means Second Isaiah. There are three primary reasons for this:
1) Critical scholars say that the poetry in chapters 44-66 is better than the poetry in chapters 1-39—that there are differences in style and vocabulary;
2) Critical scholars point to the different subject matter between the section. Chapters 1-39 deal primarily with God’s judgment, while chapters 40-66 deal with redemption and salvation, and
3) Critical scholars, by default, deny the supernatural. When Isaiah calls King Cyrus by name in Isaiah 44:28—one hundred years before he lived—multiple-author supporters cite this as an example of specific information only someone living at that time could know. Since Isaiah died long before the time of Cyrus, Isaiah obviously could not have written chapters 40-66.
Ah, but there is more: Other scholars have suggested yet a another division within chapters 4-66. They believe that another Jewish Priest or unnamed Prophet authored Isaiah 56-66 which they refer to as Trito-Isaiah or Third Isaiah.
There are, however, many fine evangelical scholars who contend for a one-author view and that author is the Prophet Isaiah. While I don’t have time to give you a detailed account, one-view supporters have ably defended the view that the Prophetic Book of Isaiah has only one author and that there is no textual evidence that the various parts of the book have ever existed as separate documents. I have no reason to doubt the one-author view.
Bottom line: You’ll probably never have to worry about this. Your chances of winning the lottery are probably better than the chances of a co-worker asking you, “So tell me, do you think the author of Trito-Isaiah was an 9th-century B.C. Jewish priest or a member of the 'school of the prophets'?” Trust me, that ain’t gonna happen. However, I thought you needed at least a brief summary of the issue.
So then, let’s turn our attention to this third section of Isaiah. It opens with promises of a grand salvation yet to come. God saves people so that they might know Him and the only way they can truly know Him is to become like Him. Those who have received the forgiveness and deliverance of God also receive grace to live as God lives. We are to live righteously. God declares, “Be ye holy because I am holy.” If God’s people will do this, all stratus of people and all the nations will come to know the Lord.
As people chose to live in obedience to God, He empowers them that they might become the servants of God. The grace of God is free, but those who receive it are expected to take hold of it in their lives and live it out. God informs those who chose grace empowered obedience that there will be rewards in their eternal salvation.
CONCLUSION: When a person is saved by the grace of God they are no longer doomed to live out life as they once did. There is power in God’s grace to live out life in faithfulness. It is not a power that one has or gains, but a power that flows from God as we become rightly related to Him. Those who surrender to live as servants of God find God’s empowering to live a life faithfulness to God.