How did Elijah prove that yaweh was the one true god?

Elijah proved that Yahweh was the one true God during the contest on Mount Carmel, where he challenged the prophets of Baal to a demonstration of divine power. Both sides prepared sacrifices but without igniting the fire themselves. While the prophets of Baal called upon their god in vain all day, Elijah prayed to Yahweh, who sent down fire from heaven to consume the sacrifice, proving His supremacy. This miraculous event led the people to recognize Yahweh as the one true God.