Now, we come to the holiest moment in the Divine Liturgy: the epiklesis (eh-PEE-klee-sis), or invocation of the Holy Spirit “upon us and these holy gifts.”
At once, God answers the elevation by His action. The priest invokes (epiklesis, “invocation”) the Holy Spirit “upon us and upon these gifts,” thus rendering the bread to be the Body of Christ and the contents of the cup to be the Blood of Christ, “changing them by Thy Holy Spirit.” We speak of metabolism in the human body as it processes material or physical energy; now, the priest mentions a special kind of metabolism (“changing,” from the Greek word, metabalon) in which the Divine Energy infuses the material gifts offered. Our reception of these gifts will be a meal, but now a very special one, for we will, by faithful partaking of them, become communicants in the divine nature. Unlike the Scholastics of old (with their “transubstantiation”), or the Protestants (with their opposite error in which they deny transfiguring grace to this mystery), we have no need to explain this dyophisitic (dual-natured) mystery: we have bread, it is the Body; we have wine, it is the Blood. Our Chalcedonian way of understanding gives us the key which holds all together, “holding the mystery of the faith in a pure conscience” (I Timothy 3: 9).
To summarize, the sacred exchange takes place: the worshipping community, represented by the presiding bishop or priest offers their whole life embodied in the bread and wine, “Thine own of Thine own.” In response, God receives this offering and “places His own Life in the Gifts, ‘the Holy for the holy’” (Elder Zacharias of Essex).
Once the epiklesis is completed, we enter the third section of the anaphora, the commemoration of the whole Catholic Church. We begin with the greatest members of the Church, the Mother of God, and the Apostles, along with all the saints, mentioning especially those saints we are commemorating on that day. The choir begins singing the megalynarion (magnification hymn) to the Theotokos, as she justly receives prime attention. During that hymn, the priest mentions all the other saints, and names among them the names of deceased Orthodox Christians who may be on the list of commemorations. At the same time, the deacon stands by the Holy Table, as he reads out the diptychs, a record of names of living and dead who are to be commemorated. We see ourselves standing by the very Altar of God, with no difference between heaven and earth, “behold, the tabernacle of God is with men” (Apocalypse 21:3). The commemorations continue with the first of importance among the living: “our father and metropolitan [Name], and our father and bishop [Name].” We receive our hierarchical authorities not as worldly princes or “strongmen,” but rather as “fathers in Christ.” In this spirit, they nourish us with apostolic teaching and authority and become the visible, personal, and concrete principle of catholic unity in the Church, “wherever the Bishop is, there is the Church” (St Ignatius of Antioch). The commemorations are only complete once every estate of Christian is mentioned, including the monastics and all the people, especially emphasized in the unique Greek way, literally “and of all men and women.”
The anaphora is concluded with a doxological exclamation in the name of the Holy Trinity, “Thine all-honourable and majestic Name of the Father and of the Son and of the Holy Spirit.” The anaphora, however, is not sealed until the whole synaxis asserts the “Amen.” Recall what St Jerome said about this, mentioned above. We have eucharistized, given thanks. “The Christ is in our midst! He is, and ever shall be!”
 At the Fourth Oecumenical Synod, held in the city of Chalcedon in the fifth century, the dogma of the “two natures” (dyo physeis) of Christ was decreed, while insisting in the utter unity of His divine-human Personhood.