Mixed in with comforting Scripture in Isaiah 40-66 are comforting commands such as Isaiah 43:1, 5.  Sermons in this section should include some analysis of God’s self-description.  Notice all the titles for God that are stated and restated.  Allow the structure of the section to drive the sermon.  In this case, God provides several reasons why His people should not be afraid.  It’s always a timely message in a scary world.  If you’re looking to allow the Gospel to give the definitive reason why we need not fear, it might be found in Isaiah 43:3-4.  Ultimately, God did not ransom us by giving us Egypt or Cush or Seba.  Instead, we were ransomed when God gave His Son “in exchange” for our lives (cf. Isaiah 43:3-4).  So, fearless Christians are those who believe Isaiah’s Gospel.