In the ACCA calendar, the Third Sunday of Pentecost, which was last Sunday this year, is the "Sunday of the Divine Body" and therefore, corresponds with the Latin Rite feast of the Body and Blood of Christ (where celebrated on Sunday), aka Corpus Christi. The Gospel reading is from John 6, either 30-46 or 47-58, and the Epistle Reading is I Cor. 11:23-28, which records St. Paul's account of the institution of the Qurbana, the Eucharist, at the Last Supper.
As is well known, John's Gospel does not record the institution of the Eucharist; however, in John 6, Jesus speaks clearly of what can only refer to the Eucharist: "the bread that I shall give is my flesh for the life of the world" and "unless you eat the flesh of the Son of Adam and drink his blood, you shall not have life within you".
Throughout the history of the Church, especially in the West, there have been various debates about the exact meaning of this Real Presence of Christ in the consecrated bread and wine of the Eucharist. Opinions have ranged from what is called transubstantiation to an outright denial of the Real Presence in some post-reformation quarters. A large problem for many following traditions flowing from the reformation is the practice of eucharistic adoration. Calvin, for example, considered such worship frank idolatry and went to great lengths to attempt to establish both that the faithful (or at least the elect) truly receive Christ in the Eucharist and that, at the same time, worship of the elements is forbidden.
Well, as they say down here, "That dog won't hunt." Beyond all philosophical theories of how Christ is present in the consecrated elements, this is the acid test: will you worship Christ so present? If the answer is "yes," you are in the mainstream of the Apostolic Tradition concerning this question. If your answer is "no," then you are not.