When God wants to change the world, He starts with a child.
Judah was about as far gone as a nation could get. Wickedness permeated every sector of society, from the palace to the priest. Yet, when it seemed all hope was lost, God had a plan. He sent Isaiah a son and used his family to change the world.
But the real hope is in the promise: "Behold a virgin shall be with child...and they shall call his name Emmanuel, which being interpreted is, God with us."