"There fell down many slain, because the war was of God." 1 Chronicles 5:22

Warrior, fighting under the banner of the Lord Jesus, observe this verse with holy joy, for as it was in the days of old so is it now, if the war be of God the victory is sure. The sons of Reuben, and the Gadites, and the half tribe of Manasseh could barely muster five and forty thousand fighting men, and yet in their war with the Hagarites, they slew "men, an hundred thousand," "for they cried to God in the battle, and He was entreated of them, because they put their trust in Him." The Lord saveth not by many nor by few; it is ours to go forth in Jehovah's name if we be but a handful of men, for the Lord of Hosts is with us for our Captain. They did not neglect buckler, and sword, and bow, neither did they place their trust in these weapons; we must use all fitting means, but our confidence must rest in the Lord alone, for He is the sword and the shield of His people. The great reason of their extraordinary success lay in the fact that "the war was of God." Beloved, in fighting with sin without and within, with error doctrinal or practical, with spiritual wickedness in high places or low places, with devils and the devil's allies, you are waging Jehovah's war, and unless He himself can be worsted, you need not fear defeat. Quail not before superior numbers, shrink not from difficulties or impossibilities, flinch not at wounds or death, smite with the two-edged sword of the Spirit, and the slain shall lie in heaps. The battle is the Lord's and He will deliver His enemies into our hands. With steadfast foot, strong hand, dauntless heart, and flaming zeal, rush to the conflict, and the hosts of evil shall fly like chaff before the gale.

Spurgeon's Daily Devotional.