In the Church we are all one and Christ is the head
"The head of the Church is Christ and we humans, we Christians, are the body. The Apostle Paul says: He is the head of the body, of the Church. (Col 1:18)
The Church and Christ are one. The body cannot exist without its head. The body of the Church is nourished, sanctified and lives with Christ. He is the Lord, omnipotent, omniscient, everywhere present and filling all things, our staff, our friend, our brother: the pillar and sure foundation of the Church. He is the Alpha and the Omega, the beginning and the end, the basis - everything. Without Christ the Church does not exist. Christ is the Bridegroom; each individual soul is the Bride.
Christ united the body of the Church with heaven and with earth: with angels, men and all created things, with all of God’s creation with the animals and birds, with each tiny wild flower and each microscopic insect. The Church thus became the fullness of Him who fills all in all, (Eph. 1:23) that is, of Christ. Everything is in Christ and with Christ. This is the mystery of the Church.
Christ is revealed in that unity between His love and ourselves: the Church. On my own I am not the Church, but together with you. All together we are the Church. All are incorporated in the Church. We are all one and Christ is the head. One body, one body of Christ: You are the body of Christ and individually members of it. (1 Cor. 12:27) We are all one because God is our Father and is everywhere. When we experience this we are in the Church. This is our Lord’s wish for all the members of the Church as expressed in His great high-priestly prayer: that they may be one. (John 17:11,22) But that’s something you can only understand through grace. We experience the joy of unity, of love, and we become one with everyone. There is nothing more magnificent!
The important thing is for us to enter into the Church - to unite ourselves with our fellow men, with the joys and sorrows of each and everyone, to feel that they are our own, to pray for everyone, to have care for their salvation, to forget about ourselves, to do everything for them just as Christ did for us. In the Church we become one unfortunate, suffering and sinful soul.
No one should wish to be saved alone without all others being save. It is a mistake for someone to pray for himself, that he himself may be saved. We must love others and pray that no soul be lost, that all may enter into the Church. That is what counts. And it is with this desire one should leave the world to retire to a monastery or to the desert.
When we set ourselves apart from others, we are not Christians. We are true Christians when we have a profound sense that we are members of the mystical body of Christ, of the Church, in an unbroken relationship of love - when we live united in Christ, that is, when we experience unity in His Church with a sense of oneness. This is why Christ prays to His Father saying, that they may be one. He repeats the prayer again and again and the apostles emphasise it everywhere. This is the most profound aspect, the most exalted meaning, of the Church."