Robyn Lebron backgrounds In fact, nearly half of the clergy of the are of a convert background The various autonomous synods of the Orthodox Church are distinct in terms of administration and local culture but, for the most part, exist in full communion with one another Tensions exist in the philosophical differences between those who use the revised Julian calendar for calculating the feasts of the ecclesiastical year and those who continue to use the traditional Julian calendar Some latent discontent between different national churches exists also in part due to different approach toward ecumenism While the ecumenical patriarch of Constantinople, the Orthodox bishops in North America gathered into the ǡ Romanian bishops and others are fairly open to dialog with the Roman Catholic Church But conservative members, many of the monks of Mount Athos, several bishops of Russian, Serbian, and some of Greek and Bulgarian churches regard cooperation as compromising doctrinal standards and object to the dialogue leading to open communion, believing instead that Orthodox must speak the truth with love in the hope of leading to the eventual conversion to Orthodoxy of Christians with doctrines that conflict with Orthodox position Those in favor of the intercommunication are currently engaged in discussing key theological differences and a possible agreement on cordial relations and eventually full communion with the Catholic and Anglican Churches Based on the numbers of adherents, Eastern Orthodoxy is the second largest Christian communion in the world after the Roman Catholic Church The most common estimates of the number of Eastern Orthodox Christians worldwide are approximately 225– 300 million individuals