The purpose of the letter to the Ephesians is unknown. The book suggests that the purpose of Ephesians is about missions and being missional. The author of Ephesians committed the task of missions to the church. The author located the mission of the church in the redemptive plan of God. The redemptive "plan" (oikonomia) of God consists of historical epochs of missions: the mission of Israel, the mission of Christ, the mission of the disciples, the mission of the apostles, and the mission of the church. The term "missional" has been used ambiguously. The existence of a distinction between the mission of the church and missional church is demonstrated, and both expressions of mission are grounded in the biblical text of Ephesians. The mission of the church is grounded in an exposition of Eph 1-3, and the missional church is grounded in an exposition of Eph 4-6. The author of the letter intended for the mission to the nations to be continued by the church (this is the mission of the church). He intended for the members of the church to continue to reach out to their local community (this is expressed by the missional church). The mission of the church has been grounded in the Great Commission. The missional church is grounded in the values, morals, and lifestyle principles set out in Eph 4-6.

Susan E. Smith provides a comprehensive history of mission that highlights the critical contributions of women, as well as the theological developments that influenced their role. Beginning with an examination of the New Testament, she goes on to review the long period between the apostolic church and the Second Vatican Council.