What was the controversy Elijah had with the prophets of Baal on Mount Carmel?
The controversy on Mount Carmel was over Israel's idolatry: despite having proof of the living God, Israel followed pagan gods and Baal. Elijah confronted all the prophets of Baal there because Israel had been following them, and this epitomized the human bent toward false worship.
Les teaches that the controversy on Mount Carmel was part of the broader problem of idolatry and pagan worship. He explains that idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, and heresies can all be lumped together in the area of idolatry or pagan worship. This has plagued the human race ever since the Tower of Babel, an innate bent to worship a false god, idols of one sort or another. Even Israel, who had the proof of the living God from their beginning and should have known better, followed after pagan gods. That was the controversy Elijah had on Mount Carmel with all the prophets of Baal, and Israel had been following them. Les also points to Jeremiah 44 as an example of this same idolatry.