Three of the earliest original manuscripts of the letter to the Ephesians do not contain the words “in Ephesus” in 1:1. This omission has led certain scholars to doubt that the letter was indeed intended for the believers in Ephesus although all the Ephesians manuscripts, including the three mentioned, have the superscription or heading: ΠΡΟΣ ΕΦΕΣΟΥΣ (“To the Ephesians”).
Many ingenious theories for the early omission of ἐν Ἐφέσῳ (“in Ephesus”) have been suggested. For example, some think the letter was intended for the whole area or province, some think that this was a very general letter that served as an introduction to all Paul’s letters and others think the phrase was omitted on purpose because of the supposedly broad-spectrum nature of the letter. However, even if we accept the omission of ἐν Ἐφέσῳ in Ephesians 1:1, this letter was still clearly associated with Ephesus from the earliest traditions. The most satisfactory reasoning therefore is that this letter was intended as an encyclical letter to the house churches of western Asia Minor, including Ephesus.
The entire Roman-Greco world, particularly western Asia Minor, was steeped in mystery religions, magic and astrology. Paul’s language and phraseology would have been understood and appreciated by all. It seems very plausible that Ephesians was an encyclical letter to the Roman province of Asia, perhaps sent first to Ephesus, the hub for communication throughout the province. The abundance of “power” language and concepts in the Ephesian letter would have particular significance and relevance to the believers in Ephesus and surrounds who lived in a very religious and superstitious era dominated by the veneration of the Ephesian Artemis.