Here youhave a detailed answer from a Serbian Orthodox.
"I will try and answer your question about the alleged appearances of the Virgin
at Medjugorje from an Orthodox point of view.
You are right in saying that the Orthodox Church does not accept these
"apparitions" as true, but it has nothing to do with the fact that they took
place on the territory of neighboring Croatia. There are many devout and good
Roman Catholic believers in Croatia and it has never been the practice of our
Church to condemn anything just because it comes from a Roman Catholic source.
However, in holy Orthodoxy we are taught to discern between spiritual delusion
(or "prelest" as the term is often used by the fathers) which is a trap one can
easily fall into, and reality. Spiritual delusion (which in worldly terms can be
likened to hypnosis, or auto-suggestion)is something very common and also very
dangerous among people who are inexperienced in the faith, yet led by their own
pride and self-sufficiency, believe that somehow God has singled them out for a
special purpose. The evil one, Satan, the father of lies, often succeeds in
trapping such people and tricking them into believing that they have been made
worthy of seeing angels, divine light, the saints, the Holy Virgin, or even the
Lord Himself. It is a well known fact, and the Apostle has written about it,
that the evil one can appear to a person as an angel of light and lead him into
terrible spititual delusion, the consequences of which can be fatal.
We Orthodox believe and know that it is first of all essential for us to
understand and repent for our sins. We are strictly forbidden to imagine
anything while we are praying - we concentrte only on the words of the prayer.
It is a long way from our fallen and sinful nature to see God or His Saints.
True, God and the Saints have appeared to people, but these appearances (and
here we will not call them "apparitions") are very different from the dramatic
occurences staged at Medjugorje.
For us ordinary people the only way to see God is in the deepest chamber of our
heart - through prayer and self contemplation.
As an illustration of how the Orthodox treat the issue of paranormal phenomena,
I would like to try and tell you a short story from the Patericon (a collection
of stories about the life of the early monastics, or the desert fathers): Once a
novice came to Abba Anthony, a well known ascetic and spiritual father of the
3rd century and said: "Abba! Father Gerasimus says he is seeing angels!" Abba
Anthony turned to him with saddness in his eyes and said: "I am not surprised he
is seeing angels. I would be surprised if he were seeing his own sins..."
Finally, may I suggest the following link to you:
http://orthodoxinfo.com/ecumenism/medjugorje.htm there you will get a much better explanation of the Marian Apparitions at
Medjugorje, Fatima and other places from an Orthodox point of view."
Ana Smiljanic