The second major background factor that we need to grasp somewhat to read Hosea well is the worship of the Canaanite god Baal(s). (The first is the Assyrian crisis, discussed here.) The name “Baal” shows up seven times in Hosea (2:8, 2:13, 2:16, 2:17, 9:10, 11:2, 13:1); four of those instances are in chapter 2. Besides these explicit references, the worship of such gods is a prominent theme in Hosea, and it would be well for anyone reading the book to have some sort of an idea of what is going on.
“Baal” was something of a general name for a variety of deities, some of which were conceptualized as being particularly localized, some of which were seen as more general gods in the polytheistic mindset of ancient Canaan. How the various religious shines serving deities known as Baals should be identified as a consistent religious movement is something of an open question (at least in my mind).
Scholars gained substantial knowledge of Baal in the archaeological site of Ugarit, which was a Canaanite city northwest of Israel up until around 1200 BC. At the site were, among many other finds, documents from the Baal cults themselves—documents which were much more sympathetic to the god and its worshippers than were the Bible and its prophets! As should be obvious even reading the Bible, the religious landscape in ancient Israel contained devotees of other gods besides Yahweh, and often a syncretistic outlook which sought to incorporate the Lord into a wider pantheon.
Basically, (severe oversimplification ahead) Baal was the god who ensured that the land yielded its crops. Baal was the rain/storm god, the god of the fertile land. Baal and his female counterpart(s) were worshiped in a cyclical patter following the seasons of the year. By ritual and sacrifice, worshippers sought to ensure that Baal would bring the rains necessary to grow crops—it was all about making sure they had food to eat.
There has been a good bit of speculation and thought of how some of the rituals associated with Baal and his female counterpart Asherah contained an explicit sexual element. As a symbol of fertility, worship at the various shrines may have included some sort of sexual ritual. In the ancient worldview accompanying such religion, the sympathetic practice of a “magical” sexual rite may have been parallel with nature, particularly the fertilization of the earth (Asherah) by the rain (Baal). The rituals were a way of manipulating the gods, thereby manipulating nature. Baal worship was all about using ritual to control the forces of nature and get what you want.
We should note at this point that commonly worship of the Lord devolves into the same thing. Hosea seems to observe such in his own day, and rails against that just as much as he does explicit worship as Baal. Worshipping Yahweh as though he were Baal is just as bad as worshipping Baal himself.
Thus, the material against idolatry in Hosea actually fits well with the themes related to Israel’s attempts to provide itself security in the face of the the threat from the rising Assyrian empire. Both are about the illusion of control—one the manipulation of politics to attain security, the other the manipulation of religion to attain abundance.
Neither is acceptable to the Yahweh of Hosea.