Hosea 2

12 I will ruin her vines and her fig trees, which she said were her pay from her lovers; I will make them a thicket, and wild animals will devour them."

'Her vines and her fig trees' are symbols of a woman's fertility, and God says that He's going to take that away from her so she can stop committing adultery. Here, it sounds like God's trying to stop her from cheating on Hosea.

13 "I will punish her for the days she burned incense to the Baals; she decked herself with rings and jewelry, and went after her lovers, but me she forgot," declares the Lord.

...and then right in the next verse, it shifts so that Gomer is actually a symbol for the Israelites. Hosea's relationship Gomer is parallel to God's relationship with the Israelites. Both the latter are the adulterous, cheating wives of their faithful husbands.

15 "There I will give her back her vineyards, and will make the Valley of Anchor a door of hope. There she will sing as in the days of her youth, as in the day she came up out of Egypt."

Although the Israelites committed this huge sin against God, He still loved them and called them back to Him. It's a perfect example of a perfect union between God and His church, because through Jesus' blood God is always taking back the one who turned on Him.