1 Kings 18:22-24

Elijah said to them: “I am the only prophet of the Lord who is left, but there are prophets of Baal.  Let them bring us two bulls. Let them choose one of the bulls for themselves, cut it up into pieces, and place it on the wood. But they must not set it on fire. I will do the same to the other bull and place it on the wood. But I will not set it on fire.  Then you will invoke the name of your god, and I will invoke the name of the Lord. The god who responds with fire will demonstrate that he is the true God.” All the people responded, “This will be a fair test.”

It's the rumble on Mt. Carmel. Elijah and the prophets of Baal are going to enter into a contest, but they are just the tools, the witnesses. The contest will be between God and Baal. The big question on the table is, "Who is truly God?" The nation of Israel has been led astray and given herself to idols and the worship of other gods. Elijah is the only prophet of the Lord left because others have been killed. God has brought Elijah here for justice, to remind Israel of who He is and that they have long since left their first love.