Isaiah and Jeremiah were prophets who had the true word of the Lord, and warned Israel and Judah of severe judgment that was coming if they did not turn back to God. But even in spite of dreadful knowledge of what was coming, they did not despair of hope. They knew God had mercy and compassion, and would not destroy the righteous with the wicked. There are hard times coming but those who keep their minds stayed on the Lord will have perfect peace. No matter what happens, God is in control and is reigning on his throne.