The ancient city of Ephesus was first colonized by Greeks in the tenth century b.c. During the first and second centuries a.d., Ephesus was the fourth largest city in the Roman Empire, a major port and trade center, and famed for its Temple of Diana, one of the seven wonders of the ancient world. According to Acts 18.19,20, Paul was the founder of the church in Ephesus. He spent almost three years there around a.d. 54–56, and was at times in difficult situations as when the silversmiths accused Paul of ruining their lucrative business in Diana souvenirs (Acts 19.23-41).
Paul's Epistle to the Ephesians is most likely a circular letter intended to be read in many churches in western Asia Minor, not just in Ephesus. This is likely since several of the most important ancient New Testament manuscripts do not have the words “at Ephesus” (1.1). Ephesians probably circulated in the region for which Ephesus was the primary church center. The fact that Paul's typical personal greetings are replaced here with a general blessing of God also suggests a circular letter. Some find this lack of any personal greeting to be odd given that Paul founded this church and had friends there.
The central theme of Ephesians is the unity of the Church, particularly in its universal dimension. Whether followers of Christ have come from Jewish or Gentile backgrounds, Paul teaches that they are one in Christ. In other letters of Paul the word “church” (Greek, ekklesia) is usually used for local congregations, but in Ephesians none of the nine uses refers to a local church. Here the word is always singular—the universal church whose oneness spans time and place. Such textual oddities alone would not rule against authorship by Paul, but along with other matters of style they have led some scholars to suggest that Ephesians may have been written after Paul's death by one of his disciples wishing to further the apostle's teachings. The letter divides into two equal halves. In the first Paul presents a thoroughly developed theology of the church universal, and what it means to be one in Christ. The second half articulates the practical implications of being one in Christ—that Christians must live in ways that express their oneness and embody the welcoming love of Christ. To equip themselves for the challenges and hardships ahead, Paul says in a beautifully poetic passage at the end of the letter, they must prepare themselves as an army would with each soldier putting on the “whole armor of God” (6.10-20). For churches encountering external persecution or internal dissention this letter offers vision and hope based in the oneness of the Church and the good purposes of God for the entire cosmos.
Greeting, Blessing of God, and Prayer (1.1-23)
Christ Brings Unity and Peace to the Church (2.1—3.21)
Living as the One Body of Christ, People of Light (4.1—6.24)