The purpose and message of Isaiah the prophet is arranged in such as way as for the reader to understand the trustworthiness of Yahweh; the covenant God. It is clearly seen in the contrast between two national leaders of Isaiah's day. Ahaz and Hezekiah. Many know the last name more than the former name. That is because Hezekiah won big time. Ahaz did not. Why? Ahaz refused to get his orders from God. Ahaz did not trust God but sent for the Assyrians to aid him in time of political crisis against the advise of the prophet Isaiah. I see the same thing happening today, our national leader is turning to 20 nations for advise and aid to bring peace. He may just succeed at bringing peace. The scriptures foretell of a man who brings peace. The people will shout peace and safety, peace and safety. Then SUDDEN DESTRUCTION will come.
The only thing that came under Ahaz's leadership style of not trusting God was one crisis after another. In fact we in America have been having one crisis after another. Why? That is what happens when you don't make God as the source.
Hezekiah, although he initially counted on Egyptian help, eventually came to fully depend on Yahweh and was delivered in a mighty way. Hezekiah is now know for how God can bring deliverance.
The purpose of a prophet is to say what God says to say. The words that are given are largely words of indictment and judgement (Chapters 1-39) In Chapters 40-60 they are more concerned with God's mercy, forgiveness, deliverance and restoration of Israel.
O God, give this nation the heart of Hezekiah and not the stiff necked heart of Ahaz.