When we take a look at clay in it's natural state, in the ground or under the soil, it is a very unstable material ... one that shifts under stress and weight .... and causes structures built upon it to collapse.
This is a good analogy of our "natural" lives ... in our natural state (sinful nature) ... we are unstable ... shifting under the stress and weight of the world around us ... and when we build our lives on it, everything comes crashing down.
But in the hands of our Father ... He molds and shapes us ... sees all our flaws ... kneads out the lumps and imperfections ... strengthens us through the fire and trials ... and creates a vessel for His pleasure.
4 And the vessel that he made of clay was marred in the hand of the potter: so he made it again another vessel, as seemed good to the potter to make it,
8 But now, O LORD, thou art our father; we are the clay, and thou our potter; and we all are the work of thy hand.