God will fight the battle

Key verses
Psalm 145:1-9 - I will exalt you, my God the King; I will praise your name for ever and ever.  Every day I will praise you and extol your name for ever and ever.  Great is the Lord and most worthy of praise; his greatness no one can fathom.  One generation will commend your works to another; they will tell of your mighty acts.   They will speak of the glorious splendor of your majesty, and I will meditate on your wonderful works.  They will tell of the power of your awesome works, and I will proclaim your great deeds.  They will celebrate your abundant goodness and joyfully sing of your righteousness.  The Lord is gracious and compassionate, slow to anger and rich in love.  The Lord is good to all; he has compassion on all he has made.

2 Chronicles
Jehoshaphat trusted in God, and God came through for him.  I read the story about Jehoshaphat defeating Moab and Ammon, described in 2 Chronicles chapter 20.  The people of Judah were wondering if they should attack Moab and Ammon, because these enemies were coming to their territory.  The people of Judah inquired of God, and the Spirit of the Lord spoke through Jahaziel who told the people of Judah not to fear.  The Lord was with them.  They wouldn't even have to fight the battle, because the Lord would fight for them.  So they went out to the place where their enemies were, and there were all the dead bodies.  The Moabites and Ammonites had fought against the men from Mount Seir, and then they turned on themselves and everyone was slaughtered.  The people of Judah didn't have to do a thing!
When you go into a difficult situation, trust in God and rely on him to come through for you (if you are in the will of God), and you will meet with success!

As a side note - what a legacy!  Here is 2 Chronicles 2:20, commenting on Jehoram's reign as king of Judah.  "Jehoram was thirty-two years old when he became king, and he reigned in Jerusalem eight years.  He passed away, to no one's regret, and was buried in the City of David, but not in the tombs of the kings."