Ephesians: The Grace of God For the Church. This book brings the grace of God into focus for everyday life in the church. The primary purpose of the church is to worship and glorify God. It is a brief exposition of Paul’s letter to the Ephesians. Paul wrote to the particular church at Ephesus, but it applies to the visible church in every age. The church is the proper place for people to experience the manifestation of God's grace.