Given its frequency, war was considered almost a way of living in the ancient Israel, as well as in the entire ancient society. The present study aims at highlighting the mission of Old Testament’s priests in the context of armed conflicts. In such situation the main activity of the Old Testament’s priests was to maintain vivid in the mind of the warriors that the Lord of Hosts is battling with them and accompanies them into war. This is illustrated mainly by the presence of the Ark of the Covenant in front of the army, carried by the Levites. Although they could not actually engage in combat, the priests used to encourage the warriors, to make sacrifices or ask for Godʹs will. In this context, the involvement of priests is a very strong argument for the presence and mission of the Church’s servants in the military units or combat scene.