Deuteronomy 31:1-8 And Moses went and spake these words unto all Israel. And he said unto them, I am an hundred and twenty years old this day; I can no more go out and come in: also the LORD hath said unto me, Thou shalt not go over this Jordan. The LORD thy God, he will go over before thee, and he will destroy these nations from before thee, and thou shalt possess them: and Joshua, he shall go over before thee, as the LORD hath said. And the LORD shall do unto them as he did to Sihon and to Og, kings of the Amorites, and unto the land of them, whom he destroyed. And the LORD shall give them up before your face, that ye may do unto them according unto all the commandments which I have commanded you. Be strong and of a good courage, fear not, nor be afraid of them: for the LORD thy God, he it is that doth go with thee; he will not fail thee, nor forsake thee. And Moses called unto Joshua, and said unto him in the sight of all Israel, Be strong and of a good courage: for thou must go with this people unto the land which the LORD hath sworn unto their fathers to give them; and thou shalt cause them to inherit it. And the LORD, he it is that doth go before thee; he will be with thee, he will not fail thee, neither forsake thee: fear not, neither be dismayed.
Moses told the entire nation of Israel not to fear, to know that God would be fighting with them. Then he took Joshua aside and told him the same thing.
God does not allow a fearful man to fight in his army because fear is contagious. If one man runs, the man next to him might run as well. And if the fear a soldier on the line is dangerous, how much more is the fear of a general? If Joshua showed fear after hearing God’s promises, it would sweep through the ranks like wind.
Fortunately, faith is also contagious. It is doubly important that leaders lead in faith and not in fear. If he stands strong, his men will stand strong. If he runs, then his men will run.
Fear not, neither be dismayed. Do what is right, and God will take care of the consequences. He will be with you. He will not fail you or forsake you.