Chapter 58. God's Challenge To His People.
This section of Isaiah is a continual plea to Israel to turn to God from sin. If the Servant's work is to be of any avail, and if Israel are to become His Servant, then sin must be dealt with and they must themselves come to Him in faith and obedience.
So in this chapter God calls on Isaiah, and each of His servants, to speak boldly to His people and bring home to them their true state. He points out why He is unable to respond to His people or answer their cries, and that is because the basis of their approach is false. And then He outlines the way by which they can alter the situation completely by responding to Him and living lives of righteousness, purity and goodness before Him, including the taking of delight in Yahweh Himself.