The reconciliation of the physical world and faith has always been difficult, especially in regards to the Eucharist and accepting bread and wine to actually be the body and blood of Christ. Father Sergius Belgakov's The Holy Grail and the Eucharist examines the most important contribution to Eucharistic Theology by an Orthodox theologian. He insists on a "properly Christological" and Gospel-based interpretation of the sacrament, while acknowledging Thomas Aquinas' interpretations as well as the Aristotelian differentiation between substance and accident.
             Fr. Sergius Belgakov states that according to Catholic theology, the Eucharist consists of a "supernatural union" of the substance of Christ's body and blood, deprived of their accidents, with the accidents of the bread and wine, which have been deprived of their substance. In this way the body and blood are offered under the appearance of bread and wine. In regards to the real presence of Christ in the Eucharist, Belgakov recognizes the contradiction between the idea of the Lord's ascension and the "Lord Himself mysteriously return[ing] to the earth and abid[ing] in the host." (page 81) In opposition, he asks that one "return[s] to the theology of the fathers, to the patristic doctrine" and to not just restate but completely the change the question being asked about the presence of Christ and the substance of Christ's body and blood.
             Belgakov goes on to examine the understanding of the heavenly food in connection with earthly food. When we eat, food, a thing of the external world becomes human body blood; thus, a natural transubstantiation occurs. In itself the food sustains mortal life, but does not assure immortality. Christ's true humanity and incarnation required that he too ate and therefore bread became "His sacred body, without losing its breadness but precisely by virtue of the latter." (page 87) The Lord's body grew and lived, obeying the universal law of th...