The subject of the book of Ephesians is vital to your existence on this planet as God's child. What does it mean to be "in Christ" as an individual and as a congregation? What does it mean to grow in Christ? These are the themes of the book of Ephesians. Paul wrote this letter to the Ephesian congregation in the middle of this pagan city of 300,000 in the ancient world. The purpose of Paul's letter is that the Ephesians needed to stop changing with the fads of the world and instead be growing and changing in Christ. The letter to Ephesians could be summarized with Paul's description of body life in Ephesians 4:15b-16, "We are to grow up in every way into him who is the head, into Christ, from whom the whole body, joined and held together by every joint with which it is equipped, when each part is working properly, makes the body grow so that it builds itself up in love." Ephesians is divided into two sections. The first three chapters are our identity in Christ, and the final three chapters are our responsibility in Christ. You cannot do what God has called you to do, until you realize what God has called you to be. Your actions always proceed from who you are. Theologians call this the indicative (our identity in Christ) and the imperative (our responsibility to walk according to our identity).