While most Christians believe similar truths about Jesus Christ, few know the proper terms that are used to describe and define these beliefs. I’m going to touch on three important words: consubstantiality, transubstantiality, and the hypostatic union. All three are used in very specific ways within Catholicism but two are certainly used by Protestants while the third may be tacitly used by some as well. If you do not already know, these words help us to understand the Trinity, the Incarnation, and the Eucharist (by which we follow the command of Christ to eat his flesh and drink his blood; see John 6:54-56).
Consubstantiality: God’s Relationship to Himself
The central dogma (which means mystery) of the Christian Faith is the mystery of the Trinity. God exists eternally as Father, Son, and Holy Spirit; three Persons fully possessing the one divine nature. In the fullness of time, God the Son was sent by the Father to reveal the inner life of God, free us of sin, and enable us to share in the eternal Trinitarian love by the power of the Holy Spirit. This may sound very mysterious and even incomprehensible. True on both counts. A mystery, however, is not something we can’t know anything about, it’s something we can’t know everything about.
In the Catechism of the Catholic Church, we read: “Jesus revealed that God is Father in an unheard-of sense: he is Father not only in being Creator; he is eternally Father in relation to his only Son, who is eternally Son only in relation to his Father: ‘No one knows the Son except the Father, and no one knows the Father except the Son and any one to whom the Son chooses to reveal him’” (CCC 240, Matthew 11:27).
Christians believe that the persons of the Trinity are consubstantial to each other. Consubstantial means that the three persons are distinct from each other but are composed of the same substance or are of the same being. In the Nicene Creed, we profess to belief that the Son is “one in being with the Father” – or as the Catechism teaches says: “…the Church confessed at the first ecumenical council at Nicaea (325) that the Son is "consubstantial" with the Father, that is, one only God with him. The second ecumenical council, held at Constantinople in 381, kept this expression in its formulation of the Nicene Creed and confessed ‘the only-begotten Son of God, eternally begotten of the Father, light from light, true God from true God, begotten not made, consubstantial [one in being] with the Father’” (CCC 242).
And if you really want to be technical/historical, the term consubstantiality is basically the Latin rendering of the Greek word homoousios which means “same substance” (homo = same, ousios = essence/substance/being).
The impact of this Trinitarian-consubstantial belief is enormous! It means that each Person of the Trinity truly is God. Some early heretics tried to assert that Jesus was just a human adopted by God or that he was made of a substance like God (homo-i-ousios), but the Church affirmed in 325 what she taught from the beginning – that each Person of the Trinity is God, distinct but united by the one divine nature. Paragraph 253 of the Catechism is worth quoting as a whole: “The Trinity is One. We do not confess three Gods, but one God in three persons, the ‘consubstantial Trinity.’ The divine persons do not share the one divinity among themselves but each of them is God whole and entire: ‘The Father is that which the Son is, the Son that which the Father is, the Father and the Son that which the Holy Spirit is, i.e., by nature one God.’ In the words of the Fourth Lateran Council (1215): ‘Each of the persons is that supreme reality, viz., the divine substance, essence or nature.’”
Hypostatic Union: Jesus Christ’s Relationship to God and Man
As I mentioned above, the mystery of the Trinity was easily misunderstood by heretics. Even more so would the Incarnation (the second great dogma of Christianity). The Incarnation, in case you’re wondering, is the belief that God the Son joined his divine self to our human nature. Why? St. Athanasius, the fourth century Church father, said it best: “The Son of God became the Son of Man so that the sons of men could become the sons of God.” God shared in our nature so that we could share in his.
Some people, however, thought Jesus was God but not really a human. Others believed Jesus was two different people – one person being God and the other being human. Still others thought that Jesus was God and man but upon ascending to heaven ridded himself of our humanity as an actor would remove a costume.
The key to understanding the Incarnation is the hypostatic union. This term was created to help articulate the beliefs of Christians since the first century. What it means is that Jesus Christ is both truly God and truly man. Furthermore, Jesus is one person, not two. “Hypostatic” means that in Jesus there is a permanent union of the divine nature with human nature. This means that from then through all eternity God joined himself to mankind and experienced all we experience, save sin. From this moment on, the human race was never the same. By the mercy of God, the dignity of the human race was elevated far higher than the nature of angels all the way to the infinity of God’s glory!
Transubstantiality: God’s Relationship to Man
Pope St. Leo the Great (from the 5th century) would follow up on this by saying: “Christian, recognize your dignity”! Leo, however, was not simply talking about mankind in general but specifically of the humans who are Christians. Why are they so special? Because they have been joined to Christ and reborn as the children of God. Biblically speaking, the Church is the body of Christ and Christ himself is the head over the body. Grace (a sharing in the very nature of God) is like the lifeblood of the body and the Holy Spirit is her soul, giving life to the body.
To take Leo in his fullness he said: “Christian, recognize your dignity and, now that you share in God’s own nature, do not return to your former base condition by sinning. Remember who is your head and of whose body you are a member. Never forget that you have been rescued from the power of darkness and brought into the light of the Kingdom of God.”
The first Christians believed the Church was both a physical and spiritual reality because her members were composed of beings that are made of both body (physical) and soul (spiritual). For 1500 years this was the universal belief of Christians. From 1520 to today, however, Protestantism has split itself up into 30,000 denominations and around 3,000 theologically contradictory schools of thought. It should not surprise one to know that they define the Church as the spiritual union of all believers.
Catholicism differs from Protestantism in that it holds the early Christian view of the Church as physical and spiritual very resolutely. For instance, Catholicism has a visible hierarchy of deacon, priest, and bishop (as did the first century Church). What makes Catholicism so very tangible, however, are the Sacraments – particularly the Eucharist.
Catholics believe the Eucharist is the very body, blood, soul, and divinity of Jesus Christ. More still, Catholics see the partaking of the Eucharist as the main source of our holiness and unity with God while living this life. You are what you eat after all – and since every Christian believes he is part of the body of Christ, it should make sense to eat the body of Christ, right? Or in the words of Jesus himself: “He who eats my flesh and drinks my blood has eternal life, and I shall raise him on the last day. For my flesh is true food and my blood is true drink. Whoever eats my flesh and drinks my blood remains in me and I in him” (John 6:54-56).
It was at this point in the Gospel in which Jesus lost many of his first disciples (John 6:66) – they just couldn’t believe Jesus’ words! After being asked by Jesus if they too wanted to leave, Peter, speaking for the Apostles, simply stated that Jesus’ words are the words of life and that there is no other place they could think to go. [Side note: Jesus usually explained his parables if people misunderstood his spiritual meaning, but in this case he was willing to let even the Apostles leave him over belief in the Eucharist!]
That the Eucharist is Christ himself has been believed since the first century, by the way. For example, St. Ignatius of Antioch (bishop from 60-107 AD and student of St. John the Apostle) said that: “The Eucharist is the flesh and blood of our savior Jesus Christ.” And while I’m at it, he also said that: “Where Jesus Christ is there is the Catholic Church.”
The big question is: how can this be? How can Jesus really give us his flesh to eat and blood to drink? This is where transubstantiality comes in. As stated earlier, Catholics believe that the Eucharist truly is the body, blood, soul, and divinity of Jesus Christ. The Catholic, however, will notice that when he eats the Eucharist it does not in any way taste like flesh and blood! This is because there was a change in substance of the bread and wine!
What does that mean?
This is a little philosophical and a little Platonic/Aristotelian but everything that exists has some spiritual substance which gives it its form/existence/life. For example, the substance of a human being is his soul. When I look at a person, I see their body – but who they are is really their soul. In other words, we could say that the body the form of the person and the soul the substance of the person.
Here’s the key to understanding why the Eucharist doesn’t taste like flesh and blood: the bread and wine are not transformed into (made to look or appear like) the body and blood of Christ, but are rather are transubstantiated into (made truly to be) the body and blood of Christ. The appearance of bread and wine remain but the spiritual reality which is the body, blood, soul, and divinity are made truly present.
Okay, all this is a pretty fancy way of trying to explain what has been believed by faith for 2,000 years. The point of it all is that through the Eucharist saints have been made! I recently spoke with a non-denominational Christian who is a big fan of IHOP (International House of Prayer) in Kansas City. What she said makes IHOP so cool is that it is one of a few places in the U.S. where people come to pray 24 hours a day. I told her I can think of thirty or so places in the Twin City area alone that have prayer chapels with people there 24/7. She was very surprised.
What makes Catholic chapels so popular and numerous is that that they are Adoration Chapels in which the very flesh, blood, soul, and divinity of Jesus Christ are exposed in the monstrance and are adored by the faithful. Why do people crawl out of bed at three in morning to pray? Because they are in the very physical presence of God!
It’s a fact, the Eucharist makes saints – and transubstantiality helps us understand how Eucharist can come into being.