I would accept the Seven Ecumenical Councils because without Christ being both fully man and fully God in union without confusion then we could not participate in the life of God and we would forever be trapped in death. This is the Gospel and this is the teaching of the Apostles and the teaching of the inspired Fathers such as Sts Athanasius, Cyril of Alexandria, John Chrysostom, Gregory the Theologian, Leo the Great and the others. The miaphysites, by refusing to say two natures to cling to the a word of St Cyril, have not properly declared the faith of St Cyril and open themselves for confusing the natures or mingling the natures, either of which would deny our being able to retain our full human nature in union with God and so our salvation because we cannot be turned into God by nature nor confused nor mingled with His nature. St Leo says something simliar: “Nor does it matter in which direction of blasphemy they disagree with the truth of the LORD ’s Incarnation, since their erroneous opinions hold neither with the authority of the Gospel nor with the significance of the mystery.” And in another letter: “For there is no new preaching in the letter which I wrote in reply to Flavian of holy memory, when be consulted me about the Incarnation of our Lord Jesus Christ; for in nothing did I depart from that rule of Faith which was outspokenly maintained by your ancestors and ours. And if Dioscorus had been willing to follow and imitate them, he would have abided in the Body of Christ, having in the works of Athanasius of blessed memory the materials for instruction, and in the discourses of Theophilus and Cyril of holy remembrance the means rather of praise-worthily opposing the already condemned dogma than of choosing to consort with Eutyches in his blasphemy.” See how St Leo turns to consistency with the Gospel and the Fathers as the rule of learning the true Faith and how this relates to the significance of the mystery.
Between Roman Catholic and Orthodox, issues between them have been raised throughout this thread. To go further in the differences between them, the distinction between essence and energies is also essential for our salvation otherwise we could not unite with God. Why? Because we must share the life of God, there is no life apart from God else God would be limited in some manner that is why those who separate from God die. We can’t share God’s nature else we would become God which is impossible because we cannot be without beginning. So, if there are no energies there is no connection with God, no participation in God, we are separate from Him and because there can be no life apart from him we die; we would never be able to exist in the first place. Rather the energies of God that are eternally of His essence yet distinct from it mean that we can share them, and participate in divine nature following St Peter’s second letter, without becoming God in nature; His life is realised in His energies and we become united and eternally sustained by them; if we are willing to accept them as our own in complete unity with God in one mind, perfect as he is perfect. Denying this distinction leads Roman Catholics to come up with another Gospel and understanding of salvation, which is not in keeping with the early Fathers. Protestants share this problem. This can also be seen in the spirituality of Orthodox Saints and Roman Catholic saints, particularly recent ones. While there are “miracles” claimed for both, beyond this the Orthodox saints, show evidence of this union with God in ways that go beyond any human level of spirituality, which by the way goes very deep even among non-Christians. The sanctity is seen in the fruits of the spirit, in love, patience, quietness, peace, joy, humility, unceasing prayer etc. These things are at a depth of character that are not momentary and unstable fruits, such as most have, but something that pervades them completely and permanently. Anyway, this is something that needs to be experienced first hand and there are not many whom one can easily meet of such spirituality. Nevertheless, on Mt Athos, in particular, there are a number of monks who are radiate much of this. I accept that there are many very pious Roman Catholics and Protestants but the spirituality to which I am referring transcends this; it is truly divine. This is also reflected in the art of the churches. Roman Catholic art since the schism became very fleshly, emotional and sentimental, as are pictures used by Protestants. The traditional iconography of pre-schism west and present day Orthodox points to something divine; it seems flat and lifeless to one accustomed to secular art but when one understands the spirit of the icons then one sees the divine in them; the transcendent peace and holiness free from passions. True spirituality frees itself from the passions, emotions and sentimentality, it becomes still in human terms but then it radiates life in divine spiritual terms. This spirituality is also seen in the actions of Patriarch Anatolius and others in reaction to St Leo’s refusal to accept Canon 28. They aimed to keep the peace, they obeyed in love as Christ commanded; this didn’t mean to say that the other was in absolute authority over them but it is an act of humility and love; this was not a sham or sign of weakness but to keep the importance of peace and unity. How do we know that they acted as such because the peace and unity was kept and yet the Patriarch of Constantinople continued to exercise all the authority that was recognised by the Canon. The Canon remained in the books and was reaffirmed at the Council of Trullo. If St Leo’s opinion was truly acknowledged in principle as an authoritative part of the Apostolic Tradition by divine will then they would have removed the Canon, the Patriarch of Constantinople would have stopped ordaining Metropolitans and the Council of Trullo would not have reaffirmed the Canon because it would be known to have been rejected by God through St Leo. Contrary to this they knew the Canon to be of Divine will and so they maintained it.