And the vessel he was making of clay was spoiled in the potter's hand, and he reworked it, into another vessel, as it seemed good to the potter to do.
The clay pot simply wasn't developing properly. Maybe it was lopsided, or too thick at the top. Maybe the base couldn't support the weight, or the clay was too wet or too dry to work. Whatever the reason, it simply wasn't coming together. So the potter reworked it, tearing down the ill-shaped pieces, fashioning the clay into something different.
We are that clay; God is the potter. If we aren't developing properly- if we are continuing to walk in sin, if we constantly chose our own way rather than His, He has the right, as the potter, to break us down and begin again.
The potter sees the process as necessary, for the vessel is of no use unless it is redone. The pot, however, may find the process rather painful. All traces of the former shape are erased, broken. Hardened bits may need to be broken off. More time is spent on the wheel, spinning in dizzying circles as the potter works.
But in the end, the vessel will be perfect, fit for exactly the purpose the potter had in mind.