In today's passage from Jeremiah, the Lord likens his care for Israel to a pottery fashioning a vessel out of clay. Now let's not make the immediate jump to some of those sappy Methodist hymns about how God is the potter and we're the clay and if we let God do everything, then everything will be alright. At least here in Jeremiah, that's not what God is getting at.
This is what Jeremiah saw: "The vessel the potter was making of clay was spoiled in his hand, and he reworked it into another vessel, as seemed good to him" (Jeremiah 18:4). God then relates that to what he can do with nations and kingdoms: "Just like the clay in the potter's hand, so are you in my hand, O house of Israel" (18:6).
What's important here is that nothing is left to fate, nothing is set in stone. With a little bit of reworking from God, whatever is broken can be made anew, whatever was ugly can be made beautiful.
If a church is dying, it's downright un-biblical to throw up our hands and say, "Let's shut it down!" without trying to let God rework it. Or if it seems that our country is on a certain course, it's un-biblical to give up and say, "Oh well, it was a good run." We must allow ourselves to be formed, to let God spin us around the wheel. This may mean that the changes are painful, and that we will look very different from what we did before. But that's good - it shows that the master craftsman is doing his job.