This chapter correlated very well with "Learning in War-Time." Although Lewis is more philosophical, Plantinga conveys the same message- just in simpler terms.
"Given Jesus' summons, his followers have always understood that to be a "Christ person" is to be a "kingdom person." Working in the kingdom is our way of life. And many followers have concluded that we need powerful Christian education to learn how to serve the kingdom most intelligently." Just as we cannot separate ourselves from secular and sacred parts of life, we cannot live on earth without living in the kingdom of God. Additionally, we must be educated so we know how to live the life that is most pleasing to God in His kingdom.
Although we already live in the kingdom, we often pray for the kingdom to come- as if it doesn't exist yet. In troubled times we pray, we beg, for the kingdom to come and save us from our misery. People who have it really bad desire the kingdom of God with every fiber of their being, but this is not a feeling most of us share. When we are having a good day, many of us secretly pray for the kingdom to come another day. We pray and hope that "your kingdom come" but not right away. This is because we think our earthly kingdom is just fine; we don't desire something better when life on earth is going great. We get too comfortable with our own way of life that the coming of the kingdom is far from our minds. I pray that I will start living in the kingdom of God instead of my own earthly kingdom; I too often think I have my own life in control and when it goes well I have no need for God. Instead of longing for God to come to me in times of sorrow, I need to acknowledge His presence is never fleeing. Our earthly kingdom, no matter how joyful it can be, will never compare to the kingdom of the Lord.
Furthermore, to say that God is the supreme ruler means that He is not the only ruler. God has created us to have dominion, so there are presidents, chiefs, chairmen, etc. "We all have a particular sphere over which we have our say." We do not reign alone though; we have our say, but only in community with others. Living in the kingdom of God means learning how to mesh our personal kingdoms with those of others. This means sharing living space, classrooms, or work space. Although we have small, personal kingdoms, God's kingdom is over all of them.
This relates to learning, because in the kingdom of God we must know how to take part in earthly kingdoms. A Christian still votes, and we have to be educated on what candidate would most glorify God. If we don't vote, we can pray for leaders to make good choices and obey them by paying taxes. There are earthly institutions that play a huge role in God's kingdom. Hospitals, schools, recreational clubs, etc. all extend God's sovereignty to every part of life. A prime citizen of the kingdom longs for shalom, so we are to participate in activities that contribute to the coming of shalom.
"God's other name is Surprise." Life is not perfectly balanced and organized, so we must be prepared for whatever God throws in our path. If we are educated in a wide array of topics, bumps in the road will not trip us up. We will be able to continue on, even if that means a new road with new sub-kingdoms. Since we are created with a desire to learn, we will not be following God's will if we are not constantly seeking knowledge. Knowledge of our Lord is what will build us up first, since He is our rock that everything stands on. If we seek God first, He will show what we need to know. I pray for a humble heart, that confesses it cannot know anything before it knows about the Lord, and that every piece of knowledge is a gift from God.