This epistle is called "Ephesians" because it is addressed to "the saints that are at Ephesus" (1:1).
From the inscription in verse 1 we learn that Paul was the writer.
Evidence indicates that Paul wrote the letter about A.D. 62 during his first imprisonment at Rome (6:20; Acts 28:30,31). Apparently it was written about the time of the Colossian letter, and Tychicus was the bearer of both (6:21; Col. 4:7; 4:16). Some scholars hold that Philemon was also sent at the same time.
Ephesus was the capital of the Roman province of Asia, and a great religious, commercial and political center. It was noted for two famous buildings: the great theatre which had a seating capacity of 50,000; and the temple of Diana, one of the seven wonders of the ancient world. Ephesus has been called the third capital of Christianity, being the center of gospel work in Asia. Jerusalem, birthplace of the church, is the first, and Antioch, center of mission work, is the second. Next to Rome, Ephesus was the most important city that Paul visited.
The Ephesian church was probably founded by Paul. He visited there toward the close of his second missionary tour and preached in the synagogue. Leaving behind him Priscilla and Aquila, he continued on to Jerusalem (Acts 18:19,21). On his third journey, Paul came to Ephesus again (Acts 19:1), and remained there about three years (Acts 19:8-10: 20:31). On the return from his third mission trip, he stopped at Miletus, 30 miles away, and sent for the elders of Ephesus to whom he delivered the famous farewell address recorded in Acts 20.
Since the words at Ephesus (1:1) do not appear in some ancient manuscripts, some suppose this letter to be "the epistle from Laodicea," referred to in Colossians 4:16. Others think that it was a circular letter to the churches of Asia Minor. Being a prison epistle, it is filled with pathos. The church, the body of Christ, is the theme. The letter is quite similar to, but also quite different from Colossians. Each is half doctrinal and half practical. Ephesians discusses church-hood, or the church as the body of Christ; Colossians discusses Christ-hood, or Christ the head of the church. From the contents we conclude that no special circumstances prompted the writing of the Ephesian letter. The general object of the epistle is to present the ground, the course, the aim and end of the Lord's church. The Ephesian assembly is, in some respects, set forth as a sample or type of the universal church. Throughout the epistle we read of the church in the singular, never in the plural. Paul shows that the origin of the church is the will of God; the course of the church is by the satisfaction of the Son; the end of the church is a life of dedication directed by the Holy Spirit through the word. The epistle is said to present the profoundest truth revealed to men. Since Paul spent such a long time among the Ephesians, perhaps no church group was better prepared to appreciate and appropriate the great spiritual principles contained in the epistle.