Deuteronomy 20

Moses would not participate in the wars he spoke of, but his words would guide those who did.  Warriors had to be free of other concerns and pursuits, and must be aware of the bigger picture.  That had to know that the conquest was God’s judgment upon the Canaanites, and to be aware of the danger involved in letting those enemies survive.  They had to be careful not to harm the land, because it would soon be their land. 

LORD, you have called us to peace, not war.  But we must sometimes wage war with the Adversary.  Teach us wise warfare.