Isaiah was a prophet in Judah during the reigns of Uzziah, Jotham, Ahaz and Hezekiah. He was active during the Assyrian occupation of Israel, sometime around 745 to 695 B.C. In particular, he advised Hezekiah, who is known for tearing down idols permitted by previous kings and for turning back the advances of Assyrian King Sennacherib.
Like many prophets, much of Isaiah’s message is a call to repentance and return to God. This call was heightened by the Assyrian takeover of Israel, the northern sister kingdom to Judah. Isaiah’s prophecies, and the interpretation of the writers of 2 Kings and 2 Chronicles, is that the fall of Israel was due to its abandonment of God and embrace of idolatry and other sins. If Judah wanted to avoid that fate, it would need to return to God.
Isaiah had a long career as a prophet, so his writings address many events of his day. These were generally threats of foreign aggression against Judah, particularly from Assyria and its allies. He also warned against alliances with Egypt because if its instability. He predicts the eventual fall of Jerusalem and it rebuilding under another empire.
He is also known for prophecies of the Messiah. These texts are often intermingled with texts referring at one moment the nation of Israel as God’s servant and next to the coming Messiah in the same terms. It’s necessary to read these passages in the context of the surrounding text to sort out when Isaiah is referring to which entity. Both Matthew and John refer to Isaiah in their gospels.
Note that much of Isaiah is written in the form of poems or songs. Sometimes he is speaking very directly to a particular nation or person about specific issues or events that are present or predicted. At other times, nations or peoples may be stand-ins for concepts or other future peoples with similar roles or viewpoints. Much of this can be sorted out by careful reading of the text and by reference to the historical books of the Old Testament.
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