Why is the split of the Church into the Orthodox and Catholic important?

Answer 1

their beliefs are a bit different in some ways

Roman Catholic AnswerFirst of all the Church did not "split" into two. The Catholic Church was established by Jesus Christ and the Holy Spirit, and God, Himself, has guaranteed to be with It until the end of time. He guaranteed that It would be ONE, Holy, Catholic, and Apostolic. So the Orthodox left the Church, in other words, they split from It; well, technically, they are in schism.

It is important because it is a major tragedy that so many people have been brought up outside the Church proper. The Orthodox do have valid Sacraments and Orders (They have a valid priesthood, Mass, and other sacraments) to that extent they are part of the Catholic Church. But they are in schism, and it is a major scandal (in the religious sense of the word: any action or its omission, not necessarily sinful in itself, that is likely to induce another to do something morally wrong.)

from A Catholic Dictionary, edited by Donald Attwater, Second edition, revised 1957

The Schism of the East the estrangement and severance from the Holy See of what is now called the Orthodox Easter Church was a gradual process extending over centuries. After a number of minor schisms the first serious, though short, break was that of Photius; from then on tension between East and West increased, and the schism of Cerularius occurred in 1054. From then on the breach gradually widened and has been definitive since 1472. There was a formal union from the 2nd Council of Lyons in 1274 until 1282, and a more promising one after the Council of Florence from 1439 to 1472. After the capture of Constantinople it was in the Turkish interest to reopen and widen the breach with the powerful Roman church; the patriarchates of Alexandria, Antioch, and Jerusalem were dragged into this policy, Russia and the Slav churches stood out the longest of any: none of these churches, except Constantinople itself in 1472, formally and definitely broke away from the unity of the Church. But in the course of centuries the schism has set and crystallized into a definite separation from the Holy See of many million people with a true priesthood and valid sacraments. The origins, causes and development of the schism are matters of much complication, still not fully unraveled.