As an Orthodox Christian, striving to know the ancient practies of our Saviour Jesus Christ Church by God's grace some few months ago I was granted to I spend few months of time with an Coptic Oriental Orthodox Christian (Medhat Baky). Before meeting with Baky, I knew not that in Egypt there are Christians at all. The little time I spend with this Oriental Orthodox was very beneficial in spiritual sense. I was amazed of the deepness in which Baky knew Christian faith. Moreover I was amazed by the Grace of this Christian as Christ's joy and presence was very powerful in him. Unfortunately for some reasons historical and political reasons Copts Orthodox are not in official communion with the Eastern Orthodox Church. Copts rejected decisions of Holy Fathers on all Ecumenical Councils after 3rd one.Interestingly the same Church which has for 20th Pope (Patriarch) saint Anthony the Great which jealously was protecting true Christianity on III-rd ecumenical council did not participated in the rest of the Church ecumenical councils. Because of that in-participation of Copts in ecumenical councils, nowdays there are some dogmatical issues, where we the Eastern Orthodox (in my view incorrectly accuse) copts for being Mia-physits (Monophisits). According to definition Mia Physis
The dogmatical problem of Monophisitism, is quite severe, according to our Orthodox Eastern understanding by monophisite we accuse Copts for believing falsely that on the Cross the divine nature of Christ suffered only. Though the Monophisitism issue holds back the true communion re-union between us and copts I believe this whole issue is more on a "phylosophical" than a faith level. Coptic Orthodox nowdays is mostly in Egypt, Ethiopia and Africa and numbers 18 000 000 members. It is interesteng to mention even though, officially they're considered divided from the Only Holy (Apostolic) Orthodox Church because of their reject of Ecumenical Council 4, 5, 6 and 7, Copts spiritual life is still preserved in the early centuries and faith in them is strong. It would be great if this 18 000 000 of Christians the whole worldwide congregation of Orthodox Christians which as of time of writting is estimated from 300 000 000 to 400 000 000 people !
Officially Copts Reject the accusation of Chalcedon ecumenical council (for disbelieving the two natures of Christ). Just for the sake of info on the Chalcedon Ecumenical council copts were judged to be heretics. Back in the day copts claim there was a political reason, as there were church fights to abolish the independent Egyptian Pope – which maintained that Church and State should not mingle.
Well anyways, I don't know who is right and who is wrong Copts or us, but what I know for sure is nomatter the dogmatical difference between us Eastern Orthodox and Oriental Orthodox in essence our faith is alsmost the same.
Coptic Church gave birth of many saints, through years many of this saints are also saints in whole Orthodox realm. Below is a nice videos I found on youtube explaining well, the basics of Copt faith and few interesting facts of their ancient faith.
Christians of the Nile Valley: An Introduction to the Coptic Orthodox Church – Part 1
Christians of the Nile Valley: An Introduction to the Coptic Orthodox Church – Part 2