Some years ago, it was pointed out to me that our relationship to God is described in several metaphorical ways, all of which matter. Some authors/teachers have even been known to rank the relationship descriptions in some way--for example, in levels of intimacy:
While I cannot argue with the theology of such a ranking, it does have the unintended side effect of causing the reader to dismiss the relationship descriptions listed earlier on the list. It's just as important to understand the potter/clay dynamic between us and God as it is anything else. He mentioned that particular picture dozens of times in books by no less than 4 biblical authors: Isaiah, Jeremiah, Paul, and John. Yes, He's our loving Father, but focusing only on Him as Father can lead us into missing out on some important truths.
We are clay, not pots
What is it about a clay and potter which describes how we are to relate to God? I've got a few, but let me first say what I believe the most important one: a clay is liquid. It's soft. It's essentially mud. Of the multiple passages which describe God as a Potter, only two of them describe us as pots, and in both of them, He reminds us that He can and will, if necessary, break us in pieces.
The idea of us being clay, as opposed to pots, is vital in our understanding that He shapes us, and is still shaping us. You are a work in progress. I am, too.
With that understanding under our belt, we can move forward in seeing what else this Potter/clay thing means:
1. Working out the bad stuff: At first, clay has things in it which shouldn't be there. The potter uses his hands to work out the impurities.
2. Shaping us: The potter shapes the clay into what he wants it to be. Sometimes, that means stretching, molding, pulling, pushing, and moving things around a bit. It's not always going to be comfortable.
3. The Sponge: while the potter's fingers make changes to the general shape, he also uses a sponge to smooth out the bumps, so that the end product will be smooth.
4. Who's in charge: The clay has no say in what shape or type of vessel it will become. The Potter decides, and will make the clay according to the potter's purposes.
5. Beginning with the end in mind: Before actually starting, the potter knows what he wants to clay to look like when finished. He sees the completed cup, jar, or pot in that lump of clay long before anyone else does.