Paul begins the letter declaring blessings to God for his blessings and love towards us. Paul then thanks the Ephesians for their faithfulness to Jesus, and says that he prays for their spiritual growth. He then tells of how God justified believers through grace (echoing the theme of Romans). Now all believers are in communion with each other and God. Even those who are not Jews can be fully saved.
In chapter 4, Paul holds unity in Christ as the standard for the church. Believers were all given spiritual gifts to build up the entire body of Christ. Furthermore, believers are to live differently than non-believers in darkness. They are to walk in the light of Christ, in love and kindness. This means no sexual immorality, crude talk, or coveting. They are to always give thanks to God. Believing wives are to submit to their husbands, and believing husbands are to love their wives as Christ self-sacrificially loved the church. Believing children are to honor their parents, fathers are to discipline and instruct their children, servants are to obey their masters, and masters are to treat their servants well, knowing that Christ is in turn their master. Paul’s last passage before his final greetings has to do with the ‘armor of God’. A believer should be careful to withstand the devil wherever he may be found, honing him or herself in Christ.
Who wrote it?
Ephesians 1:1 says that Paul wrote Ephesians.
Who was it written to?
Ephesus was an ancient Greek city located in modern-day Turkey. Paul wrote to the church there.
When was it written?
In multiple places in the letter (such as Ephesians 3:1), Paul mentions being imprisoned. This would mean the letter was written around 62 A.D., when Paul was in prison in Rome.
Why was it written?
There seems to be no major issue in the Ephesian church that Paul needed to address, as the letter covers a variety of topics. Paul did mention he wanted the church to know how he was doing (Ephesians 6:21).
How does Ephesians apply to me?
Part of Ephesians is similar to Romans in its Gospel message. Every person is born into sin, but God sent Jesus so that anyone who believes in Him is justified before God. For more on that, please see the Gospels (Matthew, Mark, Luke, and John) or Romans. As for Ephesians, it also stresses how all people should love and respect the people around them according to their relationships in life. They should also stand firm against any and all sin, with the whole armor of God.
As for all posts in this series, a book introduction in a good study Bible will provide more information than listed here. The ESV Study Bible is one recommendation.
The Bible Project video on Ephesians