The night before Jesus was betrayed by one of his closest friends, betrayed by the religious leaders of his nation and betrayed by the cowardice of Roman political expediency and so assassinated on a cross, he was spending time with his closest friends in a room upstairs where he shared a final meal with them. At this meal, which was the Jewish Passover, he resymbolised the meal to no longer be a symbol and physical memory of the Exodus from Egypt but was know to be a symbol and physical memory of his own death as our substitute. This bread is my body, this wine is my blood.
At the risk of totally oversimplifying it, there are three main teams when it comes to understanding the Lord’s Supper. There’s the Roman Catholic view which is called Transubstantiation. The idea here is that all things have two categories of properties: essence or substance and accidentals. The essence is the core of the thing, what makes the thing a thing. The accidentals are the physical sense-data of the thing: what it looks like, what it feels like, what it smells like, what it tastes like. Roman Catholics would say that in the Lord’s Supper the essence or substance of the bread and wine changes to be the actual body and blood of Jesus, while the accidentals remain the same as bread and wine. So while it looks like bread, feels like bread, tastes like bread and smells like bread, the essence or substance has been transformed. And so Transubstantiation.
Then there is the Protestant church, and within the Protestant church there are two teams. And this is where the incarnation comes into it. Because during the Reformation of the 16th century the big incarnation discussion between protestants focussed around the Lord’s Supper. On one side was Martin Luther Luther and on the other side was Huldrych Zwingli, with John Calvin weighing in as well.
So Luther held to what is called Consubstantiation, where the body and blood of Jesus was in some real sense under the bread and wine. Not that the essence of the bread and wine is transformed, as said the Roman Catholic Church, but that both essences were somehow their together. Both substances were there together, hence Consubstantiation. But how could the real physical body of Jesus be in and under the elements whenever they were present in every church in every place at every time?
The reason for it was Luther’s understanding – or misunderstanding – of the communicatio idiomatum, the communication of attributes. Luther held that the attributes of both natures in Christ, divine and human, were communicated to the other. So the human nature was divinised and so shared all the attributes of the divine. And the divine nature was humanised and so shared all the attributes of human nature. In particular, the human nature was infused with the attribute of omnipresence and so, Luther said, the human nature of Christ itself became ubiquitous, the human nature of Jesus was omnipresent. And so his human body could be in every place.
But the reason this is a mistakes because communication of attributes does not occur between the two natures, so that the divine is communicated to the human and the human communicated to the divine. But instead, the attributes of both natures are communicated to the one person of the Word.
What this means is that is right to refer to the one person of Jesus as either “God” or “Man”, since both refer to the same person. And so it is perfectly fitting when the Bible says that they “crucified the Lord of glory.” (1 Cor. 2:8) or in Acts 20:28 “Be shepherds of the church of God, which he bought with his own blood.” As if God has blood. It’s simply the case that you can refer to the humanity of Jesus with God language or to the Godness of Jesus with human language because both sets of attributes have been communicated to the one person.
It does not follow from this language that the natures have been mingled, so that Jesus divine nature now has blood or that Jesus’ human nature is omnipresent. But it is right to say that God shed his blood because the two natures are united in the one person. It’s right to ascribe what is true of one nature to the whole person.
But Jesus human body is not everywhere, because it’s still a real human body and real human bodies aren’t omnipresent. And so Zwingli claimed that in the Lord’s Supper when Jesus says, “This is my body” the word “is” means “signifies”, the Lord’s Supper is symbolic of the death of Jesus. Jesus is really present, but his presence is not the presence of his human body in the bread or wine. Because the attributes of the divine nature have not been communicated directly to the human nature of Jesus but have been communicated to his person his human nature is therefore not omnipresent and so his human nature therefore cannot be present in the Lord’s Supper.