I recently watch this excellent video regarding the ecumenistic activities of the New Calendarists and those in communion with the New Calendarists:
The actions by the hierarchs of the New Calendarists, or so-called “Orthodox Ecumenists”, is entirely foreign and unacceptable in the Orthodox Church. It is quite scandalous to see such activities, knowing that many martyrs of the Orthodox Church died because of their refusal to pray with (and, hence, refusal to recognize as valid churches) heretics.
While the ecumenistic movement in Orthodoxy may have started out with good intentions (note, however, that despite good intentions, it does not justify the actions), namely, to draw closer to the West in order to strengthen Greece’s future, the New Calendarist hierarchs have seared their conscience and it is more difficult for them to adequately stand up against this great heresy. There are those hierarchs, however, who have preserved the True Faith unadulterated in the various Orthodox lands; in Greece, the Genuine Orthodox Church of Greece, which has bishops and many parishes and monasteries here in the United States and elsewhere in the world.
So, you should ask yourself which Church, that of the Genuine Orthodox Church or the so-called “Orthodox Ecumenists”, is following the traditions of the Fathers, and when you reach your conclusion, do not hesitate to follow your conscience, lest you sear your conscience and make it harder to follow the True Path.