Give God the glory – a sermon on Ephesians 3:14-21 by Rev. Ralph Adams.
Back in 1874, Gil Dodds ran the fastest mile ever, on an indoor track. At the end of [the] race, he picked up a microphone to acknowledge [the crowd] and said: “I thank the Lord for guiding me through the race, and seeing fit to let me win… I don’t win [these] races… God [does]. You see, God has given me all I have. [But] I … [lack the one thing] … a long-distance runner… must have. I couldn’t sprint at the end of the mile. But God took care of that. In place of the ‘sprint’ he gave me stamina.” This [was surely true], because Dodds sprinted at a killing pace for the whole distance —Christian Herald 
Likewise, Paul now wants to acknowledge God by drawing our attention to the marvelous, Fatherly, care that God extends over all believers, when he says, “For this reason I bow my knees before the Father from whom [his whole family] in heaven and on earth is named.” (v.14-15)
Charles Hodge, a well-known Theologian of an earlier age, explains, “As children derive their name from their father and their relation to him is thereby determined, so the apostle says, the whole family of God derive their name from him and are known and recognized as [God’s] children.
In the verses prior to our passage (vv.11-12), Paul tells how God’s eternal purpose was accomplished in Christ Jesus and directed to the church. Under the impetus of the Holy Spirit, Paul calls ‘the church’— here, I prefer the NIV84 reading—“(God’s) whole family in heaven and on earth,” intimating that all believers are included in God’s eternal plan to some extent.
Essentially, God’s plan is as F.F.Bruce puts it, “The divine purpose, [was] to be consummated in Christ… Jewish and Gentile believers who have now been reconciled in him were already chosen in him ”before the foundation [of the] world” (Eph.1:4)… [our] final reconciliation… was decreed in Christ according to God’s ”eternal purpose.” And in the outworking of this “purpose of the ages” the people of Christ are given an essential part to play.” 
God’s eternal plan somehow includes us. People of diverse cultures can now experience unity in Christ Jesus. All those whom He has “purchased for God from every tribe and language and people and nation”  will eventually be found in the church.
Tan, P. L. (1996). Encyclopedia of 7700 Illustrations: Signs of the Times (p. 480). Garland, TX: Bible Communications, Inc.
 Hodge, C. (1996). Commentary on Ephesians (electronic ed., pp. 180–181). Simpsonville, SC: Christian Classics Foundation.
 F.F. Bruce, 1984 The Epistles to the Colossians, to Philemon, and to the Ephesians, NICNT, Wm B. Eerdmans, Grand Rapids, Michigan, p.322.
 Revelation 5:9