Christianity still exists. It exists in the Holy Scriptures, in the Fathers, in the Mysteries and the Liturgies of the Church, in monks and in laymen, but essentially it has been lost inside of us.
The proper restoration of Christianity should be basically an inner one. We could say metaphorically that the conversion of the Apostle Paul is an inner restoration of Christianity. After persecuting Christianity on the outside, he acknowledged it on the inside and it took its fitting place.
The outer restoration of Christianity might be necessary, but it is of secondary importance, whereas the inner restoration of Christianity is requisite and of foremost importance, and in the long-term could also bring about the outer restoration.
This book has been published in English translation from Theosis Books:
You can watch a short presentation from Theodore J. Nottingham here:
It has been titled “The Inner Restoration of Christianity” and you can purchase it from Amazon: