Read 2 Chronicles 14
Focus on verses 12-13
Asa was one of the few good kings of Judah. He removed the altars and shrines that had been set up to worship false gods and encouraged the people to worship and follow the Lord the God of Israel. He had ten years of peace until a massive army came up against Judah from Ethiopia. Asa took his little army of mighty men to face them and when he saw the numbers that they were up against, the text says “he cried out to the Lord for help.” I love the wording of verse twelve and thirteen as it describes for us the way it works when we walk in obedience to the will of God:
12 So the Lord defeated the Ethiopians before Asa and before Judah, and the Ethiopians fled. 13 Asa and the people who were with him pursued them as far as Gerar, and the Ethiopians fell until none remained alive, for they were broken before the Lord and his army. The men of Judah carried away very much spoil
Notice who it was that defeated the Ethiopians. Asa and his army were not passive in the ordeal, but it was not Asa and the mighty men of Judah who defeated the Ethiopians, it was the Lord who did that. What Asa and hi men had to do was clean up afterward. They chased down and killed those who were fleeing and carried off the spoil of the war, and apparently there was a lot to be carried off.
When we walk in the will of God this is how it works: God does the hard stuff – like overcoming unbelievable odds that are stacked against us. It is not that we stand around and do nothing. It would seem He expects us to be trained and ready and involved in the battle, but the point we need to remember is that it is not our might and skill that brings the victory. Without His involvement we are lost before we begin, just as Asa and the men of Judah would have been overrun and destroyed if God had not been there.
 The Holy Bible: English Standard Version (Wheaton: Standard Bible Society, 2001), 2 Ch 14:12–13.