Chosen To Unity In Christ

We have been chosen for God's glory, to be holy, and to be one body in Christ and with Christ as our head.

Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places, even as he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love he predestined us for adoption through Jesus Christ, according to the purpose of his will, to the praise of his glorious grace, with which he has blessed us in the Beloved. In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace, which he lavished upon us, in all wisdom and insight making known to us the mystery of his will, 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. (Eph 1:3-10)

In these verses it is indicated first, that even our election can not take place outside of Christ. We were chosen in Christ. Individual election is in view here because it says, "He chose us," not that He chose Christ and then we chose Christ. He chose us on the basis of the unity we were to enjoy in Christ. Not that election is dependent on our choice but on Him who has chosen to unite us to Christ.
But reading on, verses 9-10 say that He has made known the mystery of His will, which was this, "...to unite all things in him, things in heaven and things on earth." God's purpose in choosing us was to be united in Christ!
But this unity is not just of persons, but of all things. All things are to be united in Christ. This fallen world is under renovation. Through Christ all things will be set right. The lion will lay down with the lamb.

But now in Christ Jesus you who once were far off have been brought near by the blood of Christ. For he himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility by abolishing the law of commandments and ordinances, that he might create in himself one new man in place of the two, so making peace, and might reconcile us both to God in one body through the cross, thereby killing the hostility. (Eph 2:13-16)

Here is the plan by which God will make His elect one in Christ. It is by the death of Christ for those who were dead in trespasses. He has a plan to unite Jews and Gentiles, man and woman, rich and poor, and free and slave in Christ.
Here is how God is uniting all peoples together in Christ. He Himself has become our peace. In Christ we have peace with God, but we are also set at peace with the rest of the elect. He broke down the barriers between man and God, and also between Jew and Gentile. He killed the hostility that existed between ethnic groups.
Side note: Christians cannot be racists. It is impossible. It is incongruous. It goes against the purpose of God in uniting all things together in Christ. The Church is made up of people from all tribes and languages and families and ethnic groups. All nations bow to Him as their head. Racism divides the people of God into groups, but Christ unites them into one body.

This mystery is that the Gentiles are fellow heirs, members of the same body, and partakers of the promise in Christ Jesus through the gospel. Of this gospel I was made a minister according to the gift of God's grace, which was given me by the working of his power. To me, though I am the very least of all the saints, this grace was given, to preach to the Gentiles the unsearchable riches of Christ, and to bring to light for everyone what is the plan of the mystery hidden for ages in God who created all things, so that through the church the manifold wisdom of God might now be made known to the rulers and authorities in the heavenly places. (Eph 3:6-10)

God's plan is revealed first in the individual. Certain people are chosen by God. But then it moves into the corporate. We are united with the rest of the elect. Paul says his ministry was this, "to bring to light for everyone what is the plan of the mystery hidden for ages in God who created all things, so that through the church the manifold wisdom of God might now be made known to the rulers and authorities in the heavenly places." This is Paul's way of saying that through the Gospel he preached, the mystery of unity in Christ was being revealed corporately. Not only to the Church itself, but to governments and demonic forces as well.
Unity in Christ is the citizenship in Christ's kingdom. And His kingdom is not of this world. It is in the world and growing daily, gaining strength until it engulfs all things. The kingdom is spreading through the world through the Church.
Let me give an illustration that will explain a little better what I am referring to. In sanctification the child of God is being conformed to the image of Christ. This sanctification is never completed in this life. Rather, when Christ returns we will be transformed into His image. The church is spreading God's kingdom across the world. This kingdom will not be realized until the second coming of Christ, when every eye shall see Him and every knee will bow to Him.
If we learn anything from this, it should be that the Christian life is not to be lived in a vacuum. We are united together with other believers in local congregations, and then one day, the reality of our unity in Christ will be revealed to the world. We (corporately) will reign as kings and priests with Him. So put off the I, me, and mine mentality and put on Christ, in whom we have been bonded together by love.