Hosea was speaking at a time of calamities--dangers from outside and disobedience and disloyalty within.
The Lord tells him to marry a prostitute. The Lord tells him what to name the children born to them. We are struck by the names that the Lord deems appropriate: Jezreel--God sows; Lo-ruhamah--Not pitied; Lo-ammi--I am not yours.
If we choose to read this chapter metaphorically (as many commentators do), we can see the history of Israel lived out through the life of Hosea. Israel has been unfaithful. The Lord has punished Israel. Israel feels abandoned.
Yet, disobedience and punishment are not the end of the story of the Lord and Israel. Pity, compassion, and love are continuing characteristics of the Lord. God tells Hosea, "When people say that you are not my people, just tell them you are the children of the living God."