The book of Isaiah is Narrative History, Prophetic Oracle, and even a Parable (chapter 5). The prophet Isaiah wrote it at approximately 700 B.C. (Chapters 40-66, written later in his life approx. 681 B.C.). Isaiah is the first book in the section called Major Prophets. They are called Major Prophets because of the large amount of material they wrote not because their message was more important than any other prophet's was. Key personalities are Isaiah, his two sons, Shearjashub and Maher-shalal-jash-baz. Isaiah contains some of the most incredible prophecies of any book. It contains foreknowledge, in incredible details about the Messiah, and the future reign of Jesus Christ. The purpose of the book of Isaiah was to call God's nation, the nation of Judah, back to faithfulness and to declare the coming Messiah "Immanuel". God calls and commissions His prophet to declare to Judah and Israel condemnation, conviction, and ultimately great hope.