How It All Goes Down
Our story opens on a city in mourning. Jerusalem has been invaded. Judah's been caught for centuries between powerful countries in the Middle East, and this time they backed the wrong guys. Their former allies but now sworn enemies, the Babylonians, have stormed the town and taken over. They've set fires, driven people out of their homes, and reduced the city and the Temple to a pile of rubble. The Babylonians also sent all the prominent citizens into exile in Babylon. And the people who are left in town? They're basically starving in the streets. Well, when they're not being tortured and humiliated by their occupiers.
So why did this all happen? Even though the Jewish people living in Jerusalem have been God's chosen people since way back in Genesis, he's not too pleased with them right now. God was angry at the way the people were acting so he decided to let the Babylonians utterly destroy the city, including his very own Holy Temple where God's spirit hangs out when he's in town.
The author doesn't really specify exactly what the people have done. He seems to think that their political and religious leaders were a bit incompetent, (After all, they didn't think the city could be taken by force. Wrong). He also calls out the prophets for leading the people astray and not predicting this disaster. Huge mess up, guys. You're prophets, for heaven's sake. The city, personified as a degraded woman, cries out to God to reconcile with the innocent victims of the leaders' misbehavior and unfaithfulness to God.
But the major point is that the author does not blame God in the slightest. The people knew that they needed to stay in God's good graces and they didn't. He just followed through with consequences like any good parent. So how can they make things better? Well, the author recommends copious amounts of nonstop weeping, prayer, and repentance. The people need to turn back to God and hope he'll take them back. No promises, but it's worth a shot. Good luck, Jerusalem. You're gonna need it.