The letter names Paul
The clearest answer comes from the opening line. Ephesians introduces itself as a letter from Paul, an apostle of Jesus Christ, written to God's people in Ephesus. It is not an anonymous book later assigned to Paul. The writer gives his name at the start and speaks with the authority of someone sent by Christ (Ephesians 1:1).
Later, the author again calls himself Paul and describes the work entrusted to him: making known God's grace among the Gentiles, meaning the nations outside Israel (Ephesians 3:1-2). He sees his ministry as part of God's plan to bring Jewish and Gentile believers together in Christ.
Paul, an apostle of Jesus Christ by the will of God, to the saints which are at Ephesus, and to the faithful in Christ Jesus:
Paul wrote as a prisoner
Ephesians gives several personal details that fit Paul's known life and ministry. Its writer calls himself a prisoner because of Christ, asks readers to remember his imprisonment, and describes himself as an ambassador who is in bonds (Ephesians 3:1, Ephesians 4:1, Ephesians 6:20).
The book of Acts ends with Paul under guard in Rome, yet freely welcoming people and teaching about Jesus (Acts 28:30-31). Many Christians therefore understand Ephesians as one of Paul's prison letters, likely written during a period of imprisonment. The letter's main focus is not Paul's hardship, though. It is the astonishing good news that Christ has made peace and formed one new people from those who were once divided (Ephesians 2:13-16).
For which I am an ambassador in bonds: that therein I may speak boldly, as I ought to speak.
Why do some people still discuss it?
Some modern readers and scholars have wondered whether a close follower of Paul may have written Ephesians in his name. They point to its vocabulary, long sentences, and the way it speaks broadly about the church. Those are real questions worth considering carefully, and sincere Christians do not all assess the evidence in the same way.
Still, the traditional view is that Paul wrote Ephesians, and the letter itself consistently presents him as the author. It also shares central themes with Paul's other teaching: salvation is God's gift rather than something earned, believers are united with Christ, and the church is to grow into maturity and love (Ephesians 2:8-10, Ephesians 4:15-16).
How to read Ephesians well
Knowing Paul as the author can help you hear the letter personally. This is a missionary and pastor writing to Christians who need to remember who they are in Christ and learn how to live together with humility, forgiveness, and love. Paul does not leave faith as an idea. He brings it into homes, workplaces, relationships, prayer, and daily choices (Ephesians 4:31-32, Ephesians 5:1-2).
Try reading Ephesians straight through, then return to its opening chapters. Notice how often Paul speaks about God's grace, Christ's peace, and the shared identity of believers. Whether you are new to the Bible or have read it for years, this letter invites you to see the church not merely as a building or institution, but as a people being brought together in Jesus.