After Isaiah’s mission was explained to him, he enquired, "Lord, how long?" Is this a two-year call, an 18-month mission? The Lord answered, "Until the cities be wasted without inhabitant, and the houses without man, and the land be utterly desolate: And the Lord have removed men far away, for there shall be great forsaking in the midst of the land." This was, of course, prophesying of the remaining tribes being taken into captivity. How would you like to be called with the knowledge that your efforts would not change or make much difference?