Israel had followed the customs of the nations. To Elijah, they limped between two opinions. Israel could not waver; they had to choose whom they would serve.
So Ahab sent unto all the children of Israel, and gathered the prophets together unto mount Carmel.
And Elijah came near unto all the people, and said, “How long go ye limping between the two sides? if YHWH be God, follow him; but if Baal, then follow him.”
And the people answered him not a word.
Then said Elijah unto the people, “I, even I only, am left a prophet of YHWH; but Baal’s prophets are four hundred and fifty men. Let them therefore give us two bullocks; and let them choose one bullock for themselves, and cut it in pieces, and lay it on the wood, and put no fire under; and I will dress the other bullock, and lay it on the wood, and put no fire under. And call ye on the name of your god, and I will call on the name of YHWH; and the God that answereth by fire, let him be God.”
And all the people answered and said, “It is well spoken.”
And Elijah said unto the prophets of Baal, “Choose you one bullock for yourselves, and dress it first; for ye are many; and call on the name of your god, but put no fire under.”
And they took the bullock which was given them, and they dressed it, and called on the name of Baal from morning even until noon, saying, “O Baal, hear us.”
But there was no voice, nor any that answered. And they leaped about the altar which was made.
And it came to pass at noon, that Elijah mocked them, and said, “Cry aloud; for he is a god: either he is musing, or he is gone aside, or he is on a journey, or peradventure he sleepeth and must be awaked.”
And they cried aloud, and cut themselves after their manner with knives and lances, till the blood gushed out upon them. And it was so, when midday was past, that they prophesied until the time of the offering of the evening oblation; but there was neither voice, nor any to answer, nor any that regarded.
And Elijah said unto all the people, “Come near unto me;” and all the people came near unto him.
And he repaired the altar of YHWH that was thrown down. And Elijah took twelve stones, according to the number of the tribes of the sons of Jacob, unto whom the word of YHWH came, saying, “Israel shall be thy name.”
And with the stones he built an altar in the name of YHWH; and he made a trench about the altar, as great as would contain two measures of seed. And he put the wood in order, and cut the bullock in pieces, and laid it on the wood.
And he said, “Fill four jars with water, and pour it on the burnt-offering, and on the wood.”
And he said, “Do it the second time;” and they did it the second time.
And he said, “Do it the third time;” and they did it the third time.
And the water ran round about the altar; and he filled the trench also with water.
And it came to pass at the time of the offering of the evening oblation, that Elijah the prophet came near, and said, “O YHWH, the God of Abraham, of Isaac, and of Israel, let it be known this day that thou art God in Israel, and that I am thy servant, and that I have done all these things at thy word. Hear me, O YHWH, hear me, that this people may know that thou, YHWH, art God, and that thou hast turned their heart back again.”
Then the fire of YHWH fell, and consumed the burnt-offering, and the wood, and the stones, and the dust, and licked up the water that was in the trench.
And when all the people saw it, they fell on their faces: and they said, “YHWH, he is God; YHWH, he is God.”
And Elijah said unto them, “Take the prophets of Baal; let not one of them escape.”
And they took them; and Elijah brought them down to the brook Kishon, and slew them there (1 Kings 18:20-40).