The opening verse gives the author as Paul, an apostle of Christ Jesus through the will of God, writing to the saints who are at Ephesus, and the faithful in Christ Jesus. His greeting: Grace to you and peace from God our Father and the Lord Jesus Christ. Then comes one long burst of worship: God has blessed us with every spiritual blessing in the heavenly places in Christ.
Paul says God chose His people in Christ before the foundation of the world, that we would be holy and without defect before him in love. He adopted them as children. In him we have our redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace. God made known the mystery of His will: to sum up all things in Christ, the things in the heavens and the things on the earth. Three times Paul repeats that all of this is to the praise of God's glory.
Those who heard the word of the truth, the Good News of your salvation, and believed were sealed with the promised Holy Spirit. A seal marked something as belonging to its owner. The Spirit is a pledge of our inheritance. Paul then prays that God would give them a spirit of wisdom and revelation in the knowledge of him. He wants them to know the hope of His calling and the exceeding greatness of his power toward us who believe. This is the power God worked in Christ when He raised Him from the dead and made Him head over all things for the assembly, which is his body.