There are two kinds of strength and courage. There is animal strength and there is moral strength; there is animal courage and there is moral courage. And although the strength of active limbs and firm muscles and the courage which men share with the lower animals are not to be despised, but praised and sought after in their degree, yet it is to the nobler qualities the text chiefly refers when it says, "Be strong and of a good courage."
I. The need of strength and courage. God gave this word of good cheer to Joshua, and repeated it thrice over, so that he might never forget it. Joshua and his men needed it, or God would not have said it to him thrice so earnestly. You will need to hear this cheering cry: (1) in the hour of confession; (2) in the hour of temptation; (3) in the hour of misfortune; (4) in the hour of death.
II. The source of strength and courage. "Be not afraid, neither be thou dismayed, for the Lord thy God is with thee whithersoever thou goest." This is the secret. It is to have God ever near, a Friend unseen to others, but visible to us. Christ with us that will make us strong and courageous. He knows all the dangers that are before us. Our enemies are strong the wicked heart, the tempting world, the unknown future. But greater is He that is with us than they that are with them. No power can stand against us if He is on our side. And, best of all, He loves us. If we know that Christ loves us and that He has all power and knows all that is before us, what have we to fear?
J. Stalker, The New Song,p. 141.