In Paul's list of blessings accomplished by Jesus Christ, he gives us a wonderful BIG PICTURE glimpse at God's eternal purpose. In addition to redeeming us with his blood, resulting in the forgiveness of our trespasses (verse 7), in Christ we have been giving revelation; that is, knowledge of the mystery of God's plan ("making known to us the mystery of his will," v9a). Then Paul begins to unlock for us this great 'mystery' (in Scripture, a mystery is something we would not naturally know unless God reveals it to us):
...according to his purpose, which he set forth in Christ as a plan for the fullness of time, to unite all things in him, things in heaven and things on earth. Ephesians 1:9b-10, ESVThis is grand, epic language indeed! God's will, according to his purpose, which he will bring about in the 'fullness of time,' is to UNITE all things in Jesus, whether these things be in heaven or in earth. What is this talking about?
Peter O'Brien is very helpful on this point (drawing from C.C. Caragounis, Mysterion). This ReUnification means that all will bow to Christ. Christ will have the preeminence in all things, ruling in every realm. The word unite (Greek anakephalaioō) means to ‘sum up all things’ (its only other occurrence in the NT is Romans 13:9, where all the commandments are summed up in the command to love your neighbor – Stott). “Christ is the sphere in which God sums up the cosmos… God’s saving purposes, planned from eternity, had as their final goal the uniting of all things in heaven and earth in Christ.. (God is) bringing together the fragmented, alienated elements of the universe in Christ as the focal point” (O’Brien).
We cannot overstate the importance of Jesus Christ!
God purposed for Christ to rule over all and be the center of all – things in heaven (represented by the 'powers' so frequentlymentioned in Ephesians) and things on earth (represented by the church, made up of Jews and Gentiles). The obstacles to this grand purpose were the rebellion of the powers in the heavenlies, and the alienation of men from God and each other on earth (Caragounis, quoted in O’Brien).
This glorious purpose of God was accomplished at the cross, where Christ dealt the death blow to the rebellious powers (Colossians 2:15; Eph 1:20-21) and accomplished our redemption (Col 1:20-22) AND brought Jews and Gentiles together into one body (Eph 2:14-15) over which Christ rules as the Head (Eph 1:22-23)! Praise God!
...according to the working of his great might that he worked in Christ when he raised him from the dead and seated him at his right hand in the heavenly places, far above all rule and authority and power and dominion, and above every name that is named, not only in this age but also in the one to come. And he put all things under his feet and gave him as head over all things to the church... Ephesians 1:19b-22, ESVSo God's purpose for Christ to rule in the heavenlies over all powers, and in the earth over a unified Jew-Gentile church that has been reconciled to God, has been accomplished by Christ in his death and resurrection. Christ already reigns. His kingdom is here already; but the final outworkings of what was accomplished at the cross still await the ‘fullness of time.’ “History is moving towards a glorious goal” (Stott). What was won at the cross will one day be applied in experience; Christ already reigns, but one day all will know he reigns! He will be the focal point of a newly reunified universe over which he reigns in glory!
• Therefore God has highly exalted him and bestowed on him the name that is above every name,  so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth,  and every tongue confess that Jesus Christ is Lord, to the glory of God the Father. Philippians 2:9-11
Does this mean that all will be saved?
What does God's uniting of all things in Christ imply? Will all people be saved? Will even demons find grace? Some have historically used these verses to try to show that eventually all will be saved in this reunified universe where all bow to Christ. But this contradicts the clear teaching of the rest of Scripture (Matt 25:46, etc). Rather, the universe will be reconciled through either (1) peace with God through redemption in Christ for God’s people who believe, or (2) peace with God through subjection to Christ who has defeated their rebellion. “The summing up of the totality takes place in its subjection to the Head” (Stott quoting the TDNT I, p.682). The point is that all rebellion will be ended under Christ.
Let us praise the Lord, who reigns over all...and will be seen and known to reign, in every realm, forever and ever!
- The Letter To The Ephesians; Peter T. O’Brien; ©1999; Wm. B. Eerdmans Publishing Co. Grand Rapids, MI.
- The Message Of Ephesians – God’s New Society; John R. W. Stott; ©1979; InterVarsity Press, USA. Downers Grove, IL.