One scholar has described the work of the prophet as that of a “covenant enforcement mediator.” The prophet was to remind God’s people they were in an agreement with God. He was to remind them of what the agreement said. He was to rail against their disobedience, warn them of the consequences (that’s where foretelling the future came in), and call them to change. I guess, when you think about it, his job was simply that of a preacher.

The writing prophets of the Old Testament are divided into “major prophets” and “minor prophets.” “Major” and “minor” have only to do with the length of the books, not the importance of their content. There are four major prophets and twelve minor ones. The work of the writing prophets occurs after the division of God’s people into a northern kingdom -- Israel, and a southern one -- Judah, about 900 B.C. The longest of the major prophets is Isaiah and other than the Psalms, no book is cited or alluded to more often than this one.

Isaiah, a priest in Jerusalem, began his work during the final twenty years of the northern kingdom’s history. During that time, Israel’s greatest political threat was Assyria. Isaiah writes, however, not to Israel, but to Judah. He uses Israel as an object lesson. For twenty years he will decry her wicked ways, urge her to turn to God, assure her of God’s love for her, and warn her of the penalty for failure. When Isaiah’s book is finished, the southern kingdom knows that what Isaiah has been saying to the north has been true. At that time, the south’s great enemy is Babylon. Isaiah then turns his message to the south and, fundamentally, speaks the same thing to Judah.

Isaiah is divided into three parts.

I) Chapters 1 - 35 are poetry. It deals with the Assyrian threat and urges Israel to trust neither in her enemies nor her allies, but in God. There are three sections (1-12, 13-27, 28-35) and each ends with a poem of praise to God.

II) Chapters 36 - 39 are prose and tell the story of God’s deliverance of His people from her enemies and emphasize the importance of trusting God.

III) Chapters 40 - 66 are poetry and are divided into three parts (40-48, 49-57, and 58-66), each ending with a warning of judgment against the wicked. The section emphasizes the great will of God to save those who will turn to Him and his determination to judge those who will not.

Isaiah’s relevance for the Christian Church has been largely limited to foretelling of the coming of Christ, and yet, that is but a minor concern for the prophet. He is supremely interested in God’s people coming to trust in God. Those who will trust the Lord can be assured of God’s favor and protection. Isaiah 25:6-9 is but a sample of many texts that could be cited to illustrate this point: “On this mountain the LORD Almighty will prepare a feast of rich food for all peoples, a banquet of aged wine – the best of meats and the finest of wines. On this mountain he will destroy the shroud that enfolds all peoples, the sheet that covers all nations; he will swallow up death forever. The Sovereign LORD will wipe away the tears from all faces; he will remove the disgrace of his people from all the earth. The LORD has spoken. In that day they will say, "Surely this is our God; we trusted in him, and he saved us. This is the LORD, we trusted in him; let us rejoice and be glad in his salvation.” (See also Isaiah 28:16; 30:18; 40:29-31; 43:1-2; 49:13-23;65:24).

If Hebrews 11 is the great faith chapter in the Bible, and Romans the great faith book of the New Testament, then surely Isaiah has to be the great faith book of the Old Testament.