The Epistle to the Ephesians, also called the Letter to the Ephesians and often shortened to Ephesians, is the tenth book of the New Testament. Its authorship has traditionally been credited to Paul the Apostle but, starting in 1792, this has been challenged as Deutero-Pauline, that is, written in Paul's name by a later author strongly influenced by Paul's thought.
The main theme of Ephesians is “the Church, which is the Body of Christ.”
As a prisoner for the Lord, then, I urge you to live a life worthy of the calling you have received. Be completely humble and gentle; be patient, bearing with one another in love. Make every effort to keep the unity of the Spirit through the bond of peace.
The Church is to maintain the unity in practice which Christ has brought about positionally. According to New Testament scholar Daniel Wallace, the theme may be stated pragmatically as “Christians, get along with each other! Maintain the unity practically which Christ has effected positionally by his death.”
Another major theme in Ephesians is the keeping of Christ's body (that is, the Church) pure and holy.
Therefore be imitators of God, as beloved children. And walk in love, as Christ loved us and gave himself up for us, a fragrant offering and sacrifice to God.
From Ephesians 4:17–6:20 the author of the Epistle to the Ephesians gives practical advice in how to live a holy, pure, and Christ-inspired lifestyle. Many devotional thoughts and sermons that are addressed to the practically minded individual have been drawn from this section of the New Testament, due to its nature as being good for application studies.
According to tradition, the Apostle Paul wrote the letter while he was in prison in Rome (around AD 62). This would be about the same time as the Epistle to the Colossians (which in many points it resembles) and the Epistle to Philemon. However, many critical scholars have questioned the authorship of the letter and suggest that it may have been written between AD 80 and 100.
The first verse in the letter identifies Paul as its author. While early lists of New Testament books, including Marcion's canon and the Muratorian fragment, attribute the letter to Paul, more recently there have been challenges to Pauline authorship on the basis of the letter's characteristically non-Pauline syntax, terminology, and eschatology.