2 Chronicles 20

Jehoshaphat was a leader that taught the Judah to put the Lord first. He set the example for -

"...his heart was lifted up in the ways of the LORD: moreover he took away the high places and groves out of Judah." (Old Testament | 2 Chronicles 17:6)

When his people were confronted with the approaching of the armies of Ammon, Moab, and mount Seir, and with the instruction of the prophet Jahaziel saying -

"...Thus saith the LORD unto you, Be not afraid nor dismayed by reason of this great multitude; for the battle is not yours, but God's." (Old Testament | 2 Chronicles 20:15)

...it was Jehoshaphat that taught -

"...Believe in the LORD your God, so shall ye be established; believe his prophets, so shall ye prosper." (Old Testament | 2 Chronicles 20:20)

It seems as the people choose to follow the Lord and His prophets, the Lord protects His people. We see this same thing when Elisha said to his servant -

Fear not: for they that be with us are more than they that be with them.
17 And Elisha prayed, and said, LORD, I pray thee, open his eyes, that he may see. And the LORD opened the eyes of the young man; and he saw: and, behold, the mountain was full of horses and chariots of fire round about Elisha." (Old Testament | 2 Kings 6:16 - 17)

As we are faithful, the hosts of Heaven are there for our defense.