John Calvin Commentary Ephesians 1:23

"which is his body, the fulness of him that filleth all in all." — Ephesians 1:23 (ASV)

The fullness of him that filleth all in all. This is the highest honor of the Church: that until He is united to us, the Son of God considers himself in some measure imperfect. What consolation it is for us to learn that, not until we are with him, does he possess all his parts or wish to be regarded as complete! Hence, in the First Epistle to the Corinthians (1 Corinthians 12:12–31), when the apostle discusses extensively the metaphor of a human body, he includes under the single name of Christ the whole Church.

That filleth all in all. This is added to guard against the supposition that any real defect would exist in Christ if he were separated from us. His wish to be filled and, in some respects, made perfect in us arises from no lack or necessity. For all that is good in ourselves, or in any of the creatures, is the gift of his hand; and his goodness appears even more remarkably in raising us from nothing, so that he, in the same way, may dwell and live in us.

There is no impropriety in limiting the word all to its application to this passage. For, although all things are regulated by the will and power of Christ, yet the subject Paul particularly discusses is the spiritual government of the Church. Indeed, there is nothing to prevent us from viewing it as referring to the universal government of the world, but to limit it to the matter at hand is the more probable interpretation.