Among the paramount prophetic visionaries was Isaiah, who was active duringan extraordinarily lengthy period, extending from the reign of King Uzziah to that of King Hezekiah, who both ruled in Judah.
Isaiah was witness to one of the most turbulent periods in the history of Jerusalem, from both the religious and the political standpoint. Because of his social status he took an active and in some cases central part in the course of events. But his position did not prevent him from excoriating the corruption which had vitiated the ruling class and the aristocracy's obliviousness toward the downtrodden.
Isaiah is the most "political" of the prophets. In the face of the expansionist Assyrian empire he counseled a passive political and military response. He put his faith in divine salvation, which would certainly follow from a necessary change in the moral leadership and in the people's spiritual tenacity. Although he stood by King Hezekiah, Isaiah objected to his attempts to forge alliances with Egypt and with the envoys of the Babylonian king Merodach-baladan as a wedge against the Assyrians. Such efforts, the prophet said, demonstrated a lack of faith in God.
Isaiah is also considered the most universal of the prophets:"In the days to come, the Mount of the Lord's House shall stand firm above the mountains... And the many peoples shall go and shall say: 'Come, let us go up to the Mount of the Lord ... "(Isaiah 2:2-3). Christian theologists have drawn heavily on Isaiah's prophecies for exegetical purposes.