God was on Jehoshaphat's side because he stuck to the ways of his father Asa's early years. He didn't fool around with the popular Baal religion -
he was a seeker and follower of the God of his father and was obedient to him; he wasn't like Israel.
And God secured the kingdom under his rule, gave him a firm grip on it. And everyone in Judah showed their appreciation by bringing gifts. Jehoshaphat ended up very rich and much honored.
He was single-minded in following God; and he got rid of the local sex-and-religion shrines.
In the third year of his reign he sent his officials - excellent men, every one of them - Ben-Hail, Obadiah, Zechariah, Nethanel, and Micaiah on a teaching mission to the cities of Judah.
They were accompanied by Levites - Shemaiah, Nethaniah, Zebadiah, Asahel, Shemiramoth, Jehonathan, Adonijah, Tobijah, and Tob-Adonijah; the priests Elishama and Jehoram were also in the company.
They made a circuit of the towns of Judah, teaching the people and using the Book of The Revelation of God as their text.