The Lord Will Be With You In Battle.Deuteronomy 19-21.

“When you go out to battle against your enemies, and see horses and chariots and people more numerous than you, do not be afraid of them; for the Lord your God is  with you, who brought you up from the land of Egypt. So it shall be, when you are on the verge of battle, that the priest shall approach and speak to the people. And he shall say to them, ‘Hear, O Israel: Today you are on the verge of battle with your enemies. Do not let your hueart faint, do not be afraid, and do not tremble or be terrified because of them; for the Lord your God is He who goes with you, to fight for you against your enemies, to save you.’ “Then the officers shall speak to the people, saying: ‘What man is there who has built a new house and has not dedicated it? Let him go and return to his house, lest he die in the battle and another man dedicate it. And it shall be that if they accept your offer of peace, and open to you, then all the people who are found in it shall be placed under tribute to you, and serve you. Now if the city will not make peace with you, but war against you, then you shall besiege it.
Deuteronomy 20:1-5,11-12 - NKJV