Though every word of Scripture is inspired by the Holy Spirit and given to edify and instruct the church (2 Tim. 3:16–17), not every portion of God’s Word has had the same influence in Christian history. Some books of the Bible (most often due to their content) have been read, studied, and preached more than others. Therefore, they have impacted the church’s life and ministry most directly. Paul’s epistle to the Ephesians belongs to the former category, its teaching having a more evident influence on Christian theology than any other Pauline letter except, perhaps, Romans.
From the start, the church has regarded Ephesians as an authentic correspondence from the pen of the apostle Paul, written while he was in prison in the early AD 60s. It is among the first New Testament writings quoted or alluded to in the writings of the second-century apostolic fathers, which points to a very early date for this letter, and its teaching on grace and other topics align plainly with the doctrines found in the other Pauline letters. Moreover, the earliest references to Ephesians outside the New Testament agree unanimously that the apostle gave us this epistle.
Over the past two hundred years, however, about half of all biblical scholars, mostly theological liberals, have denied Pauline authorship. The reason for this denial, aside from an unspoken presupposition that the New Testament is lying until proven true, is that Ephesians possesses minor stylistic differences from the other Pauline epistles. For instance, the letter has many long sentences (Eph. 1:3–14 is one sentence in the original Greek), and it also has many words not found in Paul’s other writings. Yet this “evidence” is unconvincing. The apostle uses long sentences elsewhere (Rom. 8:28–39, for example), and arguments based on unique vocabulary have little weight because most good writers vary their terminology. At the end of the day, denial of Pauline authorship does not rest on hard facts but largely on the arrogant assumption that the apostles were simpletons who could not use words artistically.
As for the reason Ephesians was written, the fact that it does not refer to specific congregational problems gives us an important clue. Apparently, Paul intended the letter to be read in many places for the sake of instructing several churches, and individual greetings might have tied the letter too closely to one particular setting.