The Book of Ephesians, written by the Apostle Paul, is a profound letter that emphasizes the richness of God's grace and the unity of believers in Christ. Paul outlines the spiritual blessings that Christians have received in Christ—election, redemption, and inheritance—and highlights the importance of the church as the body of Christ. The letter encourages believers to live in a manner worthy of their calling by pursuing unity, love, and holiness. Ephesians is also known for its teaching on spiritual warfare, urging believers to put on the full armor of God as they stand firm in their faith.