Ephesians 1:22 and 23:

And God placed all things under his feet and appointed him to be head over everything for the church, 23which is his body, the fullness of him who fills everything in every way.

Paul has just said he prays for his readers that the eyes of their hearts would be enlightened, in order that they might come to comprehend the hope to which he has called them, the riches of God’s glorious inheritance in the Saints, and his incomparably great power for us who believe.

This power is the same power that raised Jesus from the dead, and we see it not only raised Jesus but exalted him, took him all the way to the right hand of the Father.

The same power that raised Jesus is for us, and now Christ is exalted. Vs. 21 says Jesus has been exalted:*

…far above all rule and authority, power and dominion, and every name that is invoked, not only in the present age but also in the one to come.

We, you and me, that is to say the church, are central to God’s program in the world. vs. 23a (The Message):
The church, you see, is not peripheral to the world; the world is peripheral to the church. The church, the body of Christ, matters to God and should matter to us.

What becomes clear in vs. 23 is this:

The church is Christ’s complement. (With an “e.”)
Complement: Something that fills up, completes, or makes perfect.* John Calvin:

This is the highest honor of the church, that, until he is united to us, the Son of God reckons himself in some measure imperfect. What consolation it is for us to learn that, not until we are in his presence, does he possess all his parts, or does he wish to be regarded as complete.

William Hendriksen:

As to his divine essence Christ is in no sense whatever dependent on or capable of being completed by the church. But as bridegroom he is incomplete without the bride; as the vine he cannot be thought of without the branches; as shepherd he is not seen without his sheep; and so also as head he finds his full expression in his body, the church.

Colossians 1:24:

Now I rejoice in what I am suffering for you, and I fill up in my flesh what is still lacking in regard to Christ’s afflictions, for the sake of his body, which is the church.

Here he notes that he church, in essence, completes Christ’s suffering.

vs. 23b (The Message):

The church is Christ’s body, in which he speaks and acts, by which he fills everything with his presence.

St. Teresa of Avila (1515-1582):

Christ has no body now but yours.

No hands, no feet on earth but yours.

Yours are the eyes through which he looks compassion on this world.

Yours are the feet with which he walks to do good.

Yours are the hands through which he blesses all the world.

Yours are the hands, yours are the feet, yours are the eyes, you are his body. Christ has no body now on earth but yours.

Kenneth Wuest (in his exposition of Ephesians):

The relation between Christ and the Church, therefore, is not an external relation, or one simply of Superior and inferior, sovereign and subject, but one of life and incorporation. The Church is not merely and institution ruled by Him as President, a Kingdom in which He is the Supreme Authority, or a vast company of men in moral sympathy with Him, but a Society which is in vital connection with Him, having the source of its life in Him, sustained and directed by His power, the instrument also by which He works.

The church matters to God, and should matter to me as well!