Why are the Coptics and greek orthodox not in communion?

Answer 1

This is for many reasons. Firstly, the Orthodox Church believes that it is the One True Church that was founded by Jesus Christ in 33 AD. The Roman Catholics probably also believe the same, but both can't be right, since we know that Jesus only established one church. The Orthodox and Catholics used to be united as one church for the first 1,000 years of their history, but then disagreements arose, mainly over Catholic changes to the Creed (the filioque) and Catholic claims of the supremacy of the Pope, which the Orthodox will not accept. This is because papal supremacy has never previously existed in the history of the church. The Pope is the head of the Roman Catholics, but Jesus Christ is the head of the Orthodox Church. The Orthodox Church has a collegial hierarchy of equal Patriarchs and other bishops who preside over church synods and councils. There are other reasons as well, such as the way the Eucharist is celebrated, and the manner of baptisms. The Orthodox still practice baptism by triple immersion in water, as has traditionally been the case for centuries, whereas the Catholics have changed this practice and now use sprinkling instead. It is hoped that one day unity will prevail, but this can only happen once all of these differences have been resolved.

Answer 2

The schism was caused by a disagreement at the Council of Chalcedon in 451. Wikipedia says:

"The separation resulted in part from the refusal of Pope Dioscorus, the Patriarch of Alexandria, to accept the Christological dogmas promulgated by the Council of Chalcedon, which held that Jesus is in two natures: one divine and one human. Pope Dioscorus would accept only "of or from two natures" but not "in two natures." To the hierarchs who would lead the Oriental Orthodox, this was tantamount to accepting Nestorianism, which expressed itself in a terminology incompatible with their understanding of Christology. Founded in the Alexandrine School of Theology it advocated a formula stressing the unity of the Incarnation over all other considerations."

To the Oriental Orthodox (Copts), the language of "two natures" was too close to the heretical language of Nestorianism, which, simply put, taught that Christ was two beings in one body. The Eastern Orthodox (Greeks) used the language to stress that Christ was two natures, not two persons, to emphasize that his humanity and divinity were not blended into something that was neither human nor divine. The difference was one of linguistics, not of theology, and demonstrates that the Orthodox, both Eastern and Oriental, take their language very seriously when speaking about the nature (or natures) of their God.

Both Churches have been in dialog for reunification for quite a long while. I think it is very likely that with enough effort, prayer, and open hearts, said reunification will occur this century.