Ephesians 2 starts with a hard truth. Paul tells the believers that they were once dead in transgressions and sins, following the course of this world. He includes himself: We also all once lived among them in the lusts of our flesh. Then come two powerful words, But God. God, being rich in mercy, for his great love with which he loved us, even when we were dead through our trespasses, made us alive together with Christ.
Paul gives one of the clearest summaries of the Good News: for by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, that no one would boast. Salvation is not a reward. Yet good works still matter, because they flow from what God has done. For we are his workmanship, created in Christ Jesus for good works, which God prepared before that we would walk in them.
Next Paul speaks to Gentiles. Once they were separate from Christ, alienated from the commonwealth of Israel, having no hope and without God in the world. But now in Christ Jesus you who once were far off are made near in the blood of Christ. Christ broke down the middle wall of separation and made peace, so that through him we both have our access in one Spirit to the Father. Believers are no longer strangers and foreigners. They are built on the foundation of the apostles and prophets, Christ Jesus himself being the chief cornerstone, growing into a holy temple in the Lord.