Jeremiah 21:5-8 - I myself will fight against you

21:5-7

Just in case Zedekiah was missing the point, which he clearly was, God makes it clear beyond all doubt what was going to happen. The first and most important thing was that God was against Jerusalem, His wrath was being poured out on them. Babylon was not their biggest problem, and so asking God to rescue them from Babylon was beside the point. God was their biggest problem, or rather their rebellion and perpetual sin against God. That was the issue that they needed to address, and the issue that they were steadfastly refusing to address. So death awaited them all.

21:8

The words in the previous verses seem very final, as though that is it. However, when God speaks judgement He does so looking for a response. When Jonah eventually went to Nineveh he preached a very simple message, forty days and the city would be no more. It seems stark and final, but Nineveh repented and God relented. What is final is that a people have repeatedly sinned against God and the only outcome unless they repent is judgement. So God here sets a choice before the people, a way of life or a way of death.