The antagonism of Elijah was not against Baalism in general, but against the introduction of a rival deity.
The history of Baalism among the Hebrews is obscured by the difficulty of determining whether the false worship which the prophets stigmatize is the heathen worship of Yahweh under a conception, and often with rites, which treated him as a local nature god; or whether Baalism was consciously recognized to be distinct from Yahwism from the first.
The earliest certain reaction against Baalism is ascribed to the reign of Ahab, whose marriage with Jezebel gave the impulse to the introduction of a particular form of the cult.
4) afford complete testimony for the prevalence of Baalism as late as the exile, but prove that the clearest distinction was then drawn between the pure worship of Yahweh the god of Israel and the inveterate and debased cults of the gods of the land.
How would you define baalism? Add your definition here.