[This letter is from] Paul, an apostle of Christ Jesus, according to God's will, [and is being sent] to the saints [i.e., God's holy people] at Ephesus [Note: This was a major city in the western province of Asia Minor, and now a part of Turkey. The words "at Ephesus" are omitted in some manuscripts, suggesting it was a circular letter], and the faithful ones in [fellowship with] Christ Jesus [everywhere else ?].

You practiced such things when you lived according to the evil ways of this world, and according to the ruler of the [spiritual] powers of the air. [Note: This refers to Satan, whose influence permeates life around us]. He is the [evil] spirit who is now at work in people who are disobedient [to God].

But now [that you are] in [fellowship with] Christ, you [Gentiles], who were once far away [from God], have been brought near [to Him] through the blood of Christ.

which was not told to people of previous generations as it has now been revealed to His [i.e., Christ's] holy apostles and prophets by the Holy Spirit.

This secret plan is that the Gentiles [now] share in the inheritance along with us [Jews], and are fellow-members of the body [i.e., the church], and that they share, along with us [Jews], in the promise of the Gospel, in [fellowship with] Christ Jesus.

This was done so that now God's many-sided wisdom could be made known through the church, to the rulers and authorities in the heavenly realms [Note: "Heavenly realms" here refers to the world around us, where these angelic beings (good or bad) view the unfolding of God's wonderful plan],

for you people were once darkness [i.e., when living in sin], but now you are light in [fellowship with] the Lord. [So], live like people who belong to light [i.e., who live godly lives],