Isaiah had the responsibility of speaking on God's behalf to the leaders of Jerusalem and Judah in the latter half of Israel's kingdom period. His message was one of judgement, that Israel's rebellion against their covenant with God would come at a cost, but also of hope, that God would one day fulfil all his covenant promises and so establish his kingdom. It was this hope that compelled Isaiah to speak out against the corruption and idolatry of his day. Chapters 40-46 focus on Isaiah's great hope of a new, purified Jerusalem where God's kingdom would be restored through the future Messianic King.