By the end of the Old Testament period, the people who had conquered the Promised Land were now displaced, returning from a foreign land as exiles. The nation that was supposed to bring God’s light to the world had itself fallen into darkness. As you move further through Israel’s history, you see some of the most depraved stories you’ll ever read (Judges 19, for example). Through these stories, we see how far Israel had moved from God through disobedience and idolatry.
In these books, what also becomes glaringly clear is the need for God’s salvation. He shone glimpses of light against the backdrop of such darkness. He made a covenant with David, promising a descendant that would reign as king forever (2 Samuel 7:16). The covenant would find its ultimate fulfillment in Christ (Luke 1:31–33).