It is a common practice in the Bible to use ordinary events that everyone is familiar with to teach important lessons to the people.  For instance, Jesus used the farmer sowing his crop to teach about the different responses to the word of God according to the condition of the heart.  He used the fisherman sorting the fish in his net to teach about the separation of the lost from the saved on the judgment day.

One of the more common sights in ancient days was a potter making a pot from clay.  With his feet, he would cause the wheel to spin the clay as his hands transformed a lump of clay into a pot.  The clay was always under the control of the potter's hand to make any type of pot he chose.  The total mastery of the potter over the clay is the focus of the lessons to be learned from the potter and the clay.  Isaiah uses the lesson of the potter and the clay in Isaiah 64:8.  "But now, O Lord, you are our Father.  We are the clay, and You are our potter; and all we are the work of Your hand."  We learn two important lessons.  First, God made us, and we are the work of His hands.  We should acknowledge our Maker and submit to His will.  Second, as the potter, God makes us as He chooses.  We have no right to argue against the way God designed us to be as we are.

Paul by inspiration used the same analogy.  "Does not the potter have power over the clay, from the same lump to make one vessel for honor and another for dishonor?" (Romans 9:21)  God, our potter, will make us as He chooses.  Some will be physically beautiful while others are ugly, but most will be in between.  Some will be brilliant while others will be retarded, but most will be in between.  God will make us as He chooses, and because He is the potter and we are the clay, we have no right to question why he made us as He did.

One time God told Jeremiah to go to the house of the potter where God would speak to him.  He saw the potter making a pot, but he made a mistake, so he started over and made a completely different pot.  This shows the power of God to make us or break us; to bless us or curse us and reward us or to punish us.  Since God has such total control over us, it makes sense to submit in total obedience to Him.