Ahab, king of the northern kingdom of Israel, had married Jezebel, a Canaanite sorceress and daughter of Ethbaal king of the Sidonians. Together, they sought to restore Canaanite Baal worship in the land of Israel. Ahab built a temple and an altar to Baal and Jezebel killed the prophets of Yahweh. This is a great reversal of the conquest of the land under Joshua who had driven out the Canaanites. They invited exile as Leviticus warns, “lest the land vomit you out when you make it unclean, as it vomited out the nation that was before you.”
When Elijah began his ministry he declared a drought, and for three and a half years it had not rained. Then Yahweh told Elijah, “show yourself to Ahab, and I will send rain.” This initiates the great confrontation, the battle between Yahweh and Baal. Elijah gathers all the people together along with the priests of Baal and proposes the challenge that each would call on his god and the one that answers by fire, he is God. The text makes a big point and repeats that when the priests call out to Baal “there was no voice, no one answered, no one paid attention.” Elijah mocks them and humiliates them and their worthless god.
When Elijah presents his offering, he builds an altar to symbolize all of Israel, both the northern and southern kingdoms. He lays the pieces of the bull on the altar and pours water over the whole thing, a sign that rain would come. When Yahweh answers in fire, He eats up the offering, the wood, the stones, the dust, and the water. Under the sacrificial system, a bull represented the whole people. These twelve stones are the twelve tribes. The dust harkens back to the promise given to Abraham, “your offspring will be as the dust.” The altar is consumed and the nation is spared. The people recognize Yahweh as the victor, the God of Israel. They kill the false prophets in the river valley and the rain comes and flushes their uncleanness out of the land, out into the sea.