"Holy Father, keep through Thine own name those whom Thou hast given Me, that they may be one, as We are ... Neither pray I for these alone, but for them also which shall believe on Me through their word; That they all may be one; as Thou, Father, art in Me, and I in Thee, that they also may be one in Us" (John 17:11; 20-21).
Special attention must be focused upon these words of Christ, for in them the essence of all Christianity is clearly defined. Christianity is not some sort of abstract teaching which is accepted by the mind and found by each person separately. To the contrary, Christianity is a life in which separate persons are so united among themselves that their unity can be likened to the unity of the Persons of the Holy Trinity. Christ did not pray only that His teaching be preserved so that it would spread throughout all the universe. He prayed for the unification of all those believing in Him. Christ prayed to His heavenly Father for the establishment, more correctly, for the restoration, on earth of the natural unity of all mankind. Mankind was created from one common origin and of one source (cf. Acts 17:26)....
...In the aforementioned words of Christ, the truth of the Church is placed into the tightest union with the mystery of the All-holy Trinity....
...The idea of the Church as a new, perfect community as distinct from a community of the state organization is profoundly and beautifully expressed in the kontakion for the feast of the Descent of the Holy Spirit, when the Church recalls and celebrates its beginning. "When the Most High came down and confused the tongues, He divided the nations, but when He distributed the tongues of fire, He called all into unity. Therefore, with one accord we glorify the All-holy Spirit." Here the creation of the Church is placed into opposition to the Tower of Babel and the "confusing of tongues," at which time God, the Most High, came down, confused the tongues and divided the nations....
... There are an increasing number of people among us who dream of some sort of churchless Christianity. These people have a seemingly constant anarchical system of thought. They are either incapable, or more often, are simply too lazy to think through to the end of their thoughts.
Without even speaking of the most evident contradictions of the churchless quasi-Christianity, it is always possible to see that it is completely void of the genuine Grace of Christian life, and the inspiration and quickening of the Spirit.
When people take the Gospel book, forgetting that the Church gave it to them, then it becomes like the Koran, said to have been dropped by Allah from the sky. When they somehow contrive to overlook the teaching about the Church in it, then all that remains of Christianity is the teaching, so powerless to re-create life and man, as is every philosophical system.
Our forebears, Adam and Eve, sought to become "like gods" without God, relying on the magical power of the beautiful "apple." This is how many of our contemporaries dream of being saved: with the Gospel, but without the Church and without the God-man. They hope on the book of the Gospel exactly as Adam and Eve hope on the paradise apple.
The book, however, does not have the power to give them a new life. People who deny the Church constantly speak about "evangelical principles," about evangelical teaching; but Christianity as life is completely alien to them.
In the churchless form, Christianity is only a sound, now and then sentimental, but always a caricature and lifeless. It is precisely these people who, while denying the Church, have made Christianity, in the words of V. S. Soloviev, "deathly boring." As David Strauss observed, "When the edifice of the Church is destroyed and, on the bare, poorly leveled place, there is erected only the edifying sermon, the result is sad and terrible."...
...Protestant false teaching is disgraced by this same lifelessness. What have the Protestants attained, having obscured the concept of the Church with their philosophizing? They have attained only disunity, and most hopeless disunity. Protestantism is constantly breaking down into more sects. There is no Protestant Church life, but some sort of "scarcely living" life of separate sects and communities.
Protestantism has killed the general Church life, about which the Lord Jesus Christ prayed in that first sacred prayer....
....for many of our contemporaries, the genuine Orthodox Christian ideal of the Church appeared to be too lofty. People have now become so stagnated and stiffened in their self-love, that the Orthodox concept of the Church seems to them to be some sort of coercion of personality, an incomprehensible and unnecessary despotism. The Orthodox concept of the Church demands from everyone much self-denial, humility, and love. Thus, in the hearts of our contemporaries, which are impoverished of love and for whom the dearest thing is self-love, this ideal is a burden too uncomfortable to carry.."
St. Ilarion (Troitsky), Holy New Martyr of Russia
http://www.orthodoxinfo.com/inquirers/sthilarion_church.aspx