Maintain justice and do what is right: Isaiah 1–39 emphasize the importance of justice in relationships with others and God. True godliness comes from having a character shaped by God's character, achieved by understanding and consistently applying God's word.
My salvation is coming soon: This summarizes the message of Isaiah 40–55, where the Lord is creating a world of harmony, peace, restoration, vindication, and the removal of enemies (Isaiah 46:13).