The Northern Kingdom of Israel enjoyed moderate success from conquering neighboring kingdoms, but they were spiritually bankrupt on the inside. In the Book of Hosea, God sends Hosea to Israel during King Jeroboam II's reign to admonish them of their wrongs in perpetual idol worship and dependence on outside nations.
King Jeroboam II, one of the worst kings in Israel's history, grew apathetic and allowed idol worship to run amok in the nation, opening the doorway for Israelites to cheat, steal, have unlawful sex with, and even murder each other on a constant basis. Growing cold and distant, they had forgotten about knowing God as their intimate first love, ushering in a disaster that would imminently strike through Assyria's siege. But God does not forget Israel even in their self-destruction, and He teaches us that love is the strongest force of all, even over sin.
Hope would still come through God's Messiah.