Isaiah is chief writing prophet, whose testimony is comprehensive. Known as the prophet of redemption, Isaiah and Isaiah's writings are a clear view of Grace. Grace to the church. Study Isaiah 1:1-1:27 to get a clear view of how YHWH's scattered people were deceived, turned, away from YHWH, were chastised to no avail, to believe that they were/are not the church, but that a brick and mortar building became and or is the church. Ephesians 3:3-10.