At one time there were three Popes. Peter had split into three and it took a Council of the Church to decide on one Pope among the three. Without such a Council, no one would know who was the Pope.
Orthodox and Roman Catholics have apostolic succession, but they do not venerate exactly and 100% the same saints.
As long as Roman Catholics persist in this line of discussion as we see from Steve, I doubt that EO will be enthusiastic about embracing reunion with RC.
From a logical POV, I guess you are right on this point. It is simple logic, except that I think that the ergo should be: where there is either no harmony or no unity, there is no virtue. IMHO, the statement in the CCC is wrong. I think you can find virtue in people belonging to the Russian Orthodox Church, even though they may not be in union with the Roman Catholic Church. IOW. I think you can have virtue in situations where there is not complete unity.
OK, the way this works then, using that quote “to go deep in history”,
Then show the evidence , as in going back to the 1st century on, quote from sources, where / when “Orthodox Church” 1st appears in history, in writing, properly referenced… right?
Orthodox who came back to the Catholic Church would disagree.
Allow me to quote an Eastern Catholic bishop whose Church was previously Orthodox.
In a Q/A (emphasis mine)
A: “When the Patriarchate of Antioch was divided into two branches in 1724, one branch kept the name Orthodox and the other branch which sealed its union with the Holy See of Rome, kept the name Melkite given to it since the Sixth Century and called itself Catholic. It became known as the Melkite Greek Catholic Church. In the Middle East, although both branches claim orthodoxy as well as catholicity, however being Catholic means not Orthodox and being Orthodox means not Catholic.
To be a Catholic Christian means that one accepts the primacy of the Pope of Rome, because he is the successor of St. Peter. To be an Orthodox Christian means that one does not recognize the primacy of the Pope of Rome, but considers him as “first among equals.”
According to the Catholic teaching, Christ did not create a church with five heads of equal importance. He established One Holy Catholic and Apostolic church whose invisible head is the Lord, but whose visible head is the Pope of Rome.
The Code of Canons of the Eastern Churches states it in these terms: “The bishop of the Church of Rome, in whom resides the office (munus) given in a special way by the Lord to Peter, first of the Apostles and to be transmitted to his successors, is head of the college of bishops, the Vicar of Christ and Pastor of the entire Church on earth; therefore in virtue of his office (munus) he enjoys supreme, full, immediate and universal ordinary power in the Church which he can always freely exercise.” (Canon 43 of the Code of Canons of the Eastern Churches) If an Orthodox subscribes to the Canon quoted above, he/she can be called Catholic and be considered “united to Rome” or in full communion with the Catholic Church.”
This is a good place to give references properly referenced.
Are you aware of the recent schism of the Russians and Constantinople, meaning the Russians are not in union with those Orthodox who are in union with Constantinople as well. http://www.ncregister.com/daily-news/eastern-orthodox-breach-russian-orthodox-church-splits-from-constantinople
You know full well that his views don’t represent the Catholic Church. On the other hand, there are Orthodox clergy who not only condemn us as schismatics and heretics, but also proclaim even our baptism to be null and void. You will never find a Catholic polemicist who goes to the length some Orthodox do in their contempt for Catholicism. Orthodoxy has no official / consistent teaching on Catholicism… while Catholicism officially recognizes the Orthodox Churches as sister churches with valid sacraments.
Re: “sister churches” and context
Your right. I was speaking to those saints of the first millennium, although, maybe even then there could be some that are not venerated by both Churches. However, we do have Saint Gregory Palamas on our calendar.
You have referenced this document several times and the last paragraph is interesting, “12. Finally, it must also be borne in mind that the expression sister Churches in the proper sense, as attested by the common Tradition of East and West, may only be used for those ecclesial communities that have preserved a valid Episcopate and Eucharist.”
So a sister Church is one who’s “ecclesial communities have preserved a valid Episcopate and Eucharist.” Let’s look at the Second Vatican Councils Decree on Ecumenism, Unitatis Redintegratio, “These Churches, although separated from us, possess true sacraments, above all by apostolic succession, the priesthood and the Eucharist, whereby they are linked with us in closest intimacy. Therefore some worship in common (communicatio in sacris), given suitable circumstances and the approval of Church authority, is not only possible but to be encouraged.”
This Decree on Ecumenism states that the Churches of the East who are not in communion with Rome possess “apostolic succession” and “the Eucharist.” According to the document you referenced, what make a Church a sister Church(?), " . . . those ecclesial communities that have preserved a valid Episcopate and Eucharist."
the 2nd link which you didn’t mention, was given for clarification.
“when it is a question of the principles on which to build unity, … the [Universal Catholic] Church  cannot be considered a sister [e.g. to the Orthodox Churches (2)], but rather the Mother of the local Churches.”
The Note on the Expression Sister Churches sought to make more precise the conditions under which the use of the term is appropriate. The Note said that it is possible for individual local churches (dioceses) to refer to each other as sister Churches. It is appropriate then for Popes and Ecumenical Patriarchs to refer to each other as heading sister Churches which in this case are the diocese of Rome and the diocese of Constantinople. In is not possible for the Catholic Church as a whole to refer to the Orthodox as a whole as sister Churches.
So the Orthodox are still sister Churches when speaking of local Churches.
From the “Notes” (footnotes operational)
(all emphasis mine)
“It must always be clear, when the expression sister Churches is used in this proper sense, that the one, holy, catholic and apostolic Universal Church is not sister but mother of all the particular Churches.”
“11. One may also speak of sister Churches, in a proper sense, in reference to particular Catholic and non-catholic Churches; thus the particular Church of Rome can also be called the sister of all other particular Churches. However, as recalled above, one cannot properly say that the Catholic Church is the sister of a particular Church or group of Churches. This is not merely a question of terminology, but above all of respecting a basic truth of the Catholic faith: that of the unicity of the Church of Jesus Christ. In fact, there is but a single Church, and therefore the plural term Churches can refer only to particular Churches.”
“Consequently, one should avoid, as a source of misunderstanding and theological confusion, the use of formulations such as « our two Churches ,» which, if applied to the Catholic Church and the totality of Orthodox Churches (or a single Orthodox Church), imply a plurality not merely on the level of particular Churches, but also on the level of the one, holy, catholic and apostolic Church confessed in the Creed, whose real existence is thus obscured.”
Yes, the Catholic Church as a whole but at the local level the expression sister Churches may be used. Here is the sentence just before the one of which you quoted, “10. In fact, in the proper sense, sister Churches are exclusively particular Churches (or groupings of particular Churches; for example, the Patriarchates or Metropolitan provinces) among themselves.”
There are two examples of this in the document. First, “Therefore, there prevailed and still prevails among Eastern Christians an eager desire to perpetuate in a communion of faith and charity those family ties which ought to exist between local Churches, as between sisters.»” and, " 7. The first papal document in which the term sisters is applied to the Churches is the Apostolic Brief Anno ineunte of Paul VI to the Patriarch Athenagoras I. After having indicated his willingness to do everything possible to «re-establish full communion between the Church of the West and that of the East,» the Pope asked: «Since this mystery of divine love is at work in every local Church, is not this the reason for the traditional expression “sister Churches,” which the Churches of various places used for one another? For centuries our Churches (Rome and Constantinople) lived in this way like sisters, celebrating together the ecumenical councils which defended the deposit of faith against all corruption. Now, after a long period of division and mutual misunderstanding, the Lord, in spite of the obstacles which arose between us in the past, gives us the possibility of rediscovering ourselves as sister Churches.»
So, the Pope, as the bishop of the diocese of Rome and the Ecumenical Patriarch, as the bishop of Constantinople, can refer to each other as heading sister Church.
So there is no confusion, note the following is a quote. (emphasis mine)
“However, as recalled above, one cannot properly say that the Catholic Church is the sister of a particular Church or group of Churches. This is not merely a question of terminology, but above all of respecting a basic truth of the Catholic faith: that of the unicity of the Church of Jesus Christ. In fact, there is but a single Church,”
Typically, what one really means, I would think, is that the Latin Church, which is a particular Church within the Catholic Church, and any given Orthodox Church, are sister churches. The Latin Church and the various Eastern Catholic Churches are sister Churches in full communion with, and thus comprising the Catholic Church. The various Eastern and Oriental Orthodox Churches are sister Churches in an imperfect communion with the same Catholic Church.
98% of Catholics are members of the Latin Church, so we often get lazy and conflate the Catholic Church and the particular Church to which most Catholics belong.
As I already pointed out, that is not their official name. It is like saying show me where as going back to the 1st century on, quote from sources to show where the name Vatican Church first appears in history, properly referenced,. I don’t see anyone using the name Vatican Church, so the Church of Pope Francis in the Vatican, cannot be the true religion.