Peach-trees, the Hypostatic Union, and the Christian life


by Dermott J Mullan


Summary: To grow in Christ means making choices analogous to those Christ Himself made while he was on earth: do I operate through unaltered human nature or through a divinized version of human nature?




Suppose I were to tell you that a peach-tree had started growing out of my elbow, complete with  branches, leaves, and fruit. Would you believe me? Probably not.


And for good reason. Since I am a human being, I possess human nature, and it is that nature which determines what I can and cannot do.  I can (among other things) talk and walk and reason and laugh and sing, but I cannot (among other things) fly, leap over tall buildings, or live at the bottom of the ocean.


Moreover, it is beyond the powers of my human nature to grow the branches and leaves and fruit of  a peach-tree.


The nature of a peach-tree is quite different from human nature. Peach-tree nature ensures that nutrients are taken in from the air and from the ground so that every year there is a new growth of branches, leaves, and fruit. Therefore, if a peach-tree were to start to grow out of my elbow, an observer would be forced to conclude that I must somehow have developed the nature of a peach-tree. At the very least, I must share in that nature to some extent.


The very thought of a peach-tree growing out of my elbow seems nothing short of bizarre. How could it be possible for me to have (or to share in) two natures simultaneously? And even if it were possible, would it not lead to disorder in my life? Would I have any control over where the next branches or leaves or fruit of the peach-tree would start to pop up?


So what does a peach-tree have to do with following Christ? Well, not very much in a direct sense. But it raises graphically the issue of what would happen if I were indeed able to share in two distinct natures. Is such a thing even possible? Has it ever happened? When? And to whom? Has it anything to do with my own life? The answers to those questions have a direct bearing on my life as a Christian.


The Fatherhood of God


The Church teaches that baptism introduces each of us in a real way into the family of God. On one particular day, my parents brought me to the Church and the waters of baptism flowed over me.  From that day on, I was enabled to call on God as Father. And not just figuratively either. He really is a Father to me now.


What does it mean to be a Father? In the biological realm, the answer is obvious: it means to pass on life to a new member of the species. But from the point of view of philosophy, it is more customary to define fatherhood as the process of passing on to another being a share in one’s nature.


From the perspective of philosophy, therefore, if I am to take the Church’s baptismal teaching literally (and there is no reason why I should not do so), I have for many years now been sharing (somehow) in the divine nature of God.


The Catechism of the Catholic Church proposes this teaching in the words: “The Word became flesh to make us partakers of the divine nature” (CCC 460).  And at every Mass, the priest reminds us: “may we come to share in the divinity of Christ who humbled himself to share in our humanity".



St John the Evangelist’s reaction


Although the teaching that I can call on God as Father is common Catholic teaching, it is nonetheless an amazing truth. So amazing that even St John the evangelist marveled at the immensity of the gift that had been given to him and his fellow Christians:  “See what love the Father has bestowed on us that we are called the children of God”. The immensity of this prospect, stunning as it is, comes through in St John’s  next phrase, with its air of near-incredulity: “And yet that is what we are....we are God’s children now”  (1 John 3:1-2). One can almost see St John shaking his head in wonder over the concept: “And yet...”


Why should St John have marveled at the idea that he (or anyone else) might have God as Father? Why should he have marveled at the idea that he or I can actually share to some extent in the nature of God?


Well, even at the human level, the idea of sharing two natures sounds very strange. You probably thought of me as crazy when I told you that I am now sharing the nature of a peach-tree. So why should you believe it now when someone suggests that I can share in the nature of God? After all, at least at the molecular level, I share some similarities with a peach-tree: we both use the same amino acids and rely on the same DNA code. On the other hand, there is an infinite distance between any creature and God.


But for St John, there was more at stake. He had personally experienced something that we have not experienced.  He had come face to face in his own life with a particular Person who actually did possess two natures. That Person (Jesus) was human, but He also possessed the nature of God. And not just “to some extent” as you and I do: instead Jesus actually possessed the Diving nature in all its fullness. In the words of another Apostle: “It pleased God to make absolute fullness reside in Him [Jesus]” (Col. 1:19).


The first encounter between St John and this Divine Person held little promise of the immensity of what was to ensue.  Jesus had asked him “What are you looking for?” Then there came an invitation that would change everything:  “Come and see” (John 1:38-39). From that time on, St John would find out, up close and personal, how someone who shared two natures would behave in the rough and tumble of everyday human life. 


In trying to express this experience,  St John writes his first epistle with words that struggle to give the best possible account of what must have been a mystery almost beyond the powers of human language to express: “This is what we proclaim: what was from the beginning, what we have heard, what we have seen with our eyes, what we have looked upon, what our hands have touched– we speak of the word of life...What we have seen and heard we proclaim in turn to you

so that you may share life with us. This fellowship of ours is with the Father and with His Son Jesus Christ....God is light” (1 John 1:1-5).


So, to return to my baptismal day, how can it possibly be true (as the Church teaches) that I am to share the nature of this amazing Person who had impressed St John so profoundly? How can I share human nature and Divine nature at the same time?


To answer that, it is helpful to re-visit a message that was first given by the Church almost sixteen hundred years ago, but is still relevant today.



Two questions about Jesus Christ: what? and who?


The inhabitants of first century Palestine who walked and talked with Jesus face to face would not have questioned the fact that He had a human nature. After all, most of the time, Jesus behaved and looked like a “regular” human being. He ate and drank, he slept, he worked, and “was tempted in every way we are” (Hebr. 4:15).


But eventually, some of those people became aware of the fact that there is more to Jesus than “regular human nature”. They could see that He was doing certain things which are simply not within the power of human nature. These would include miracles and healing sins, activities which belong only to the nature of God. Some of those people eventually arrived at the belief that Jesus and God share an identity in some way (Matt. 16:16; John20:28).


The problem that such people faced, when they tried to convey their beliefs to outsiders, was clear: we know Jesus has a human nature, and yet He sometimes does things which are beyond the power of human nature. How can this be? The answer is not easy to describe in human language.


A gathering of bishops at Ephesus


In fact it took four hundred years after the death of Jesus before some of the sharpest thinkers on the planet came up with an answer. These thinkers were several hundred bishops who gathered in the city of Ephesus in Asia Minor. The bishops in council were deeply versed in the philosophical language that had been developed by the Greeks. Two words from the language of philosophy emerged as of special importance at Ephesus: nature and person.


The advantage of these two apparently abstruse philosophical concepts is that they supply answers to the two very different questions we posed in the title of this section. Nature answers the question: “what?” while Person answers the question “who?”


Starting with these questions, the fathers at the Council of Ephesus in the year 431 zeroed in on the human words that seemed best suited to solving the two key questions: what is Jesus? and who is He? Is He a human person or a Divine person?


The first question “What is Jesus?” leads us to the question of nature: what nature did Jesus possess? The Council of  Ephesus taught that Jesus does indeed possess in the fullest sense a human nature but that He also possesses the Divine nature. Each of the natures retains its own powers, with no confusion between the two. That means: Jesus can do everything that is within the power of human nature (talk, walk, reason, laugh, sing), but He can also do everything that is within the power of Divine nature (create, heal, walk on water).


So far, so good: this teaching would have presented little difficulty to people who had seen Jesus behave sometimes like a human being and sometimes like God.


But now came the punch line: in answer to the question “Who is Jesus?”, the fathers of Ephesus answered: He is the second Person of the Blessed Trinity. The fathers of Ephesus ruled out another possibility which some people wanted to believe, namely, Jesus is a human person. The fathers of Ephesus taught in no uncertain terms that the latter statement is wrong: in fact, Jesus is not a human person. Jesus is only one Person, a divine Person. There is no human person at work in any of the actions of Jesus.


This is a truly amazing teaching. One must admit that there is a mystery at work in Jesus. No-one can claim to understand how Jesus actually combines two natures in a single Person. But the fathers of Ephesus, with guidance from another Divine Person, came up with the best that human language can do.


The “What?” and the “Who?” were not considered pointless questions by the citizens of the day. On the contrary, mobs in Ephesus demonstrated on both sides of the issue throughout the three months of the council. So high did emotions run in the city that, in order to preserve the peace, he chief champions of both sides were at one point thrown into jail by the Emperor. In the end, the mob carried the Pope’s legate in a triumphant torchlight procession through the streets. (Imagine if, after Vatican II, mobs had carried Pope Paul VI through the streets of Rome!)


“Hypostatic Union


An enduring technical term entered into Church teaching after Ephesus. This term comes from the Greek word for person (“hypostasis”). The fact that two natures are united in a single person is described as the “Hypostatic Union”.


The danger of using such a technical term is that people’s eyes may glaze over when they hear it. There is a temptation to think that this term is so far removed from everyday life that there is no need to pay attention.


And yet the term has a direct relevance to my personal living of the Christian life. In order to appreciate in everyday terms the significance of the teaching of Ephesus, let us to go back in imagination to Nazareth, to the house of the Holy Family, while Jesus was living there.


Jesus moves some furniture


Let us say that Mary and Joseph ask Jesus to move a piece of furniture from one part of the house to another. The question is: how will Jesus do it?


He has a choice. On the one hand, He can operate through His Divine nature and simply use His will to make the furniture move. It will immediately do so.


On the other hand, Jesus is also free to choose to operate through His human nature. If He decides to go that route, it will mean that He has to apply his muscles and sweat to push and pull and rock the piece back and forth just as you or I would do. If the piece is too big, He may even  ask for help from some of the neighbors. Eventually, after some effort, the furniture will be moved.


Now the interesting question that the fathers of Ephesus invite us to consider is the following: who moved the furniture?


In the first case, the answer is obvious: a Divine Person, specifically, the second Person of the Trinity. But what about the second case? The surprising aspect of the Ephesus teaching is that the answer is exactly the same as in the first case: the furniture was moved by the second Person of the Trinity. To be sure, human efforts were made, and human muscles and sweat were brought into play. However, all of those efforts were made not by a human person, but by the second Person of the Trinity, operating through His truly human nature.


The implications of this teaching are far-reaching. No matter what Jesus did that other human beings can do, whether it was tying His shoelaces, or singing, or sneezing, it was always the second Person of the Trinity who performed those actions. In each case, He simply made the choice to operate through His human nature.   


And in particular, on Calvary, the one who performed the (very) human act of dying was the second Person of the Trinity. Despite the inherently human nature of the act, the death on Calvary was certainly not the act of a human person. Instead, God the Son really experienced death. It is nearly impossible to grasp the staggering nature of the event of Good Friday: God, whose nature it is to simply exist, actually experienced death on the Cross. No wonder that St Paul wants us to remember this death at every Holy Communion (1 Cor. 11:26).


Also, since every action of Christ was really and truly an action of God the Son, when someone raises the issue “Could Jesus have sinned?”, the answer is clear: Jesus could not sin. Why not? Because if (mirabile dictu) Jesus were to commit a sin, the performer of the action would be God the Son. In other words, God the Son would have to break His own law, which is absurd.


Throughout the life of Jesus, when He was faced with any human task, He always had the choice of which nature to operate through. He could operate either through His human nature or through His Divine nature. The choice was up to Him. And He did have a human will, as well as a Divine will, so He was really and truly free, in both His human nature as well as in His Divine nature, to make a choice either way.



The “Hypostatic Union” in everyday Christian life    






In my life as a Christian, I am called to live as Christ did. This is not meant to be a superficial process. On the contrary, so deep is this supposed to go that I am to have “the mind that was in Christ Jesus” (Phil 2:5). It is easy to see how I can approach things such as prayers and sufferings in such a way as to develop an overlap with the mind of Christ.


But as we have seen, one of the essential aspects of Christ’s life was the choice to operate either in His human nature or in His Divine nature. Is there any analog of that choice in the life of an ordinary Christian?


There seems to be little or no problem with the “choice” to operate within the bounds of human nature. To react in human ways to the events of everyday life is “natural”. One might even say that the word “choice” is barely applicable:  it is almost instinctive to react to certain stimuli in certain ways. It is, as they say, “only human”.




But if we are to believe the Church’s teaching on baptism, then each baptized person also shares in the Divine nature. To be sure, we do not possess the Divine nature in it fullness as Jesus did: it is impossible for a human person, possessed of a finite human nature, to do so. However each of us who has been baptized does share in the Divine nature to some extent.


This suggests that, although we are not in possession of the full Hypostatic Union as Jesus was, still, there are some similarities. We certainly possess human nature, but there is also “some” of the Divine nature in us. Without wishing to sound flippant, it is as if we are in possession of a sort of “quasi-hypostatic union”.


The conclusion of this is inevitable: I am presented with the possibility of “re-enacting” to some extent the choices that confronted Jesus every day of His life. In any given circumstance, do I choose to operate strictly within the confines of my human nature? Or will I choose to operate in the framework of the other (Divine) nature in which I now share?


If I choose the latter, then I will be able to perform certain actions that are beyond the power of human nature to perform. I will be able to “practice the virtues”.


As long I choose to operate solely within the limits of human nature (and it is certainly “natural” to do so), it seems likely that I will remain in a condition that differs little (or not at all) from someone who has never been baptized.


But with God’s help, there are times when a baptized person responds in a way that goes beyond what human nature would find possible. In such an instance, it is because a choice has been made to operate according to the Divine nature. Then things may happen that must appear well-nigh impossible for an un-baptized person.




Practising the virtues


An example of virtue that looms large in my memory concerns a family which underwent the tragedy of having one of their sons murdered. At the funeral Mass, during the prayers of the faithful, the priest stopped when he came to one particular prayer: it was an intercession for the welfare of the murderer. The priest announced that he himself had not chosen this prayer: the parents had asked for it. Twenty years and more have passed since that funeral Mass, but I have never forgotten the incident. To me, the parents’ request seemed to go beyond mere human nature. Looking back on the incident, I now consider this as evidence that those parents had made a choice to operate in the context of the Divine nature which they had shared since baptism.


When baptized people practice the Christian virtues, they are making choices to operate through the Divine nature which they share. The practice of such virtues makes for a distinct sort of life from that which emerges from practicing only the actions which are “natural” to human nature.


Certain properties begin to emerge in the life of virtuous Christians. Some of these have been enumerated by St. Paul: “love, joy, peace, patient endurance, kindness, generosity, faith, mildness, chastity” (Gal. 3:22). The Church has come to refer to those properties as the “fruits of the Spirit”.


This brings us back to the peach-tree. No-one would deny that if the leaves and fruit of a peach-tree started to sprout from my elbow, it would be an event which is beyond the powers of human nature. Similarly, I submit that when the fruits of the Spirit start to appear in someone’s life, they should be considered also as events which are beyond the powers of human nature alone.


The fruits of the Spirit, and virtues, can be regarded as just as much a marvel as if peaches had started to appear. Among some of my own acquaintances, it is apparent that the fruits of the Spirit are emerging. Such people are apparently making choices to operate through the Divine nature that they have shared since the day of their baptism.


It is a blessing to know such people.