In Jeremiah 18, God told the prophet Jeremiah to go to the potter's house, and the Lord would give him a message. The Potter is like God, and Israel is the clay (and by expansion, so are we). The Potter works with marred clay and can reshape and reform how He sees fit.
This passage provokes many questions on God's sovereignty and free will. How are we to understand the relationship between the 2? The potter and clay analogy gives some insight.
Nonetheless, the best clay for the Potter to work with is submissive and malleable.
