The Jewish people wanted their cake & eat it too, and this extended to their worship. Baal was the dominant Canaanite god of rain and fertility of the land, so they thought they could hedge their bets by appeasing both God & Baal at the same time. But anytime you dabble in the occult, you’ll get sucked into things you don’t want. So before they knew it, the people found themselves worshipping Baal in the ritualistic dance around the altar, (called a limping dance). So Elijah had come to call them into account for prostituting themselves to foreign gods, forsaking their One true God, and breaking covenant with Him.