“The king of Israel said to Jehoshaphat, “I will enter the battle in disguise, but you wear your royal robes.” So the king of Israel disguised himself and went into battle. When the chariot commanders saw Jehoshaphat, they thought, “Surely this is the king of Israel.” So they turned to attack him, but when Jehoshaphat cried out, the chariot commanders saw that he was not the king of Israel and stopped pursuing him.” – 1 Kings 22:30, 32-33 NIV

Notice how Jehoshaphat entered the battle here. In previous verses we can see he knew God did not decree victory and yet joined anyway. This is foolishness.

“So the king of Israel brought together the prophets—about four hundred men—and asked them, “Shall I go to war against Ramoth Gilead, or shall I refrain?” “Go,” they answered, “for the Lord will give it into the king’s hand.” But Jehoshaphat asked, “Is there no longer a prophet of the Lord here whom we can inquire of?”” – 1 Kings 22:6-7 NIV

He knew the prophets of Ahab weren’t telling the truth to the king and then got the truth straight from God from Micaiah:

“The king of Israel answered Jehoshaphat, “There is still one prophet through whom we can inquire of the Lord, but I hate him because he never prophesies anything good about me, but always bad. He is Micaiah son of Imlah.” “The king should not say such a thing,” Jehoshaphat replied.” – 1 Kings 22:8 NIV

And Micaiah prophesied failure and death:

“Then Micaiah answered, “I saw all Israel scattered on the hills like sheep without a shepherd, and the Lord said, ‘These people have no master. Let each one go home in peace.’ ” Micaiah declared, “If you ever return safely, the Lord has not spoken through me.” Then he added, “Mark my words, all you people!”” – 1 Kings 22:17, 28 NIV

Now it was completely foolish for Jehoshaphat to enter into battle knowing that God’s decree was for failure in attacking their enemy. This is because it put Israel and Judah in harms way for no real gain. Let’s not make foolish decisions like this as God’s people. Let’s make wise ones when we know what we are supposed to do and when we know what steps we are supposed to take.