Where I live, the dirt has a lot of clay in it. So much that if you pick up some mud you can mold things out of it and it will still hold that shape when it dries. I made a tiny rose and tiny teacup out of it once. But because it’s not just clay and contains other dirt as well, it doesn’t make a very good rose or teacup. It doesn’t really make good pottery or a good sculpture at all unless you separate out the clay from the rest of the types of dirt.
I’ve seen someone do this separating of clay from other dirt. You get your clay-filled dirt and very, very thoroughly mix it with a lot of water in a container. Break up all the clods and particles. Get that dirt all shaken up and disturbed so that the water is muddy. Once the dirt is all saturated with water, you might have to disturb it all again. As it sits still, all the dirt starts to settle into layers. After straining the muddy water that’s left on top you can get the clay you want. You might have to repeat this process to get rid of the residual non-clay dirt. Once you have workable clay, you have to knead it for a while to be sure it’s the right texture for its intended purpose.
Some of you saw the metaphor coming when this post started. God can’t mold you into what you’re supposed to be until He gets the mud and silt out of the clay. That means you have to get really shaken up. You also have to sit still for a while. Then you need some straining. Then you have to be gently but firmly worked over some more to be sure you’re pliable for what God would like to mold you into. There are more steps after that, like actually being molded, waiting around a little more, and going through fire, but once you’re done, you can be used for something now. When God gets a hold of you, you are no longer useless dirt on the ground, now you’re something special that God can use for His good purposes!
Clay can’t cleanse itself of impurities. Clay can’t mold itself. Clay can’t make itself stronger. But with some work from the Potter, clay can be much more than it ever would have been if it had been left on its own.