The courage is a commandment! Courage doesn't mean that we are not afraid. It means that we fear God more than we fear our environment. It means that we trust in divine power more than the power of man.
And our courage rests in the knowledge that God is Present and He is able to defeat any foe that threatens His children.
Therefore be of good courage; be strong in the Lord; be obedient to his word; trust Him; He is the Lord our God!