What do you do with Discouragement?

Exodus 6:8-9 
8 And I will bring you to the land I swore with uplifted hand to give to Abraham, to Isaac and to Jacob. I will give it to you as a possession. I am the Lord.’”
​9 Moses reported this to the Israelites, but they did not listen to him because of their discouragement and harsh labor.

Joshua 1:9
9 Have not I commanded thee? Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee whithersoever thou goest.

Galatians 6:9
9 And let us not be weary in well doing: for in due season we shall reap, if we faint not.