I. Introduction
The Nicene Creed (more precisely, the Niceno-Constantinopolitan Creed of 381) is something we recite at Mass every week (with limited exceptions). At my parish, it’s chanted, but it remains the profession of faith that the General Instruction of the Roman Missal calls for. This year marks the 1700th anniversary of the Council of Nicaea, and I wanted to take the opportunity to look a little more closely at this foundational statement of belief.
As I write this, I’m returning to the Church after a long absence. I’m reconnecting with my faith, re-catechizing myself, and trying to deepen my understanding of Christianity. One change I’ve noticed is the English translation of much of the Mass and its prayers. This, of course, includes the Creed itself. One line that stood out to me is the updated rendering: Christ is now said to be “consubstantial with the Father,” whereas I grew up hearing “one in being with the Father.” I wanted to explore this difference with you.
Although Latin is the official language of the Catholic Church, the Creed wasn’t originally composed in Latin but in Greek. That linguistic quirk has shaped some of the complexity and nuance around this phrase.
II. The Greek Text and Meaning
The First Council of Nicaea was convened by Emperor Constantine in 325 A.D. to address the teachings of Arius, who argued that the Son was created and therefore not fully divine. In response, the bishops adopted the term ὁμοούσιος (homoousios) to declare that the Son shares the same divine essence as the Father.
The line in question is:
ὁμοούσιον τῷ Πατρί (homoousion tō Patri): “of the same essence as the Father.”
The word ὁμοούσιος combines ὁμός (homós), meaning “same,” and οὐσία (ousía), meaning “being” or “essence.” In Latin, this was rendered as consubstantialis, from con- (“with” or “together”) and substantia (“substance”). This language affirms that the Son is not a creature but is fully God, sharing the same divine reality as the Father. With the Holy Spirit, they form the Trinity: three divine Persons in one Godhead.
In my experience, Trinitarian theology is perhaps the most difficult Christian doctrine to grasp. Every time I think I’ve found a clear, simple way to explain it, I usually discover I’ve stumbled into a heresy, usually modalism. At Nicaea, this central dogma was under serious threat, not only from Arianism but also from strains of subordinationist thought influenced by Origen. Interestingly, the word ὁμοούσιος never appears in Scripture itself, yet it became the defining term that required ecumenical consensus.
In Greek, “essence” or “being” is the key idea. Personally, I tend to prefer “essence” here, though in other philosophical contexts I have leaned toward “being.”
III. The Latin Translation
The Latin feels a bit clunkier to me, simply pairing con- (“with” or “together”) with substantia (“substance”). Yet this pairing was deliberate: by the fourth century, substantia already carried philosophical weight, serving as the standard Latin translation of οὐσία going back to pre-Christian Greek philosophy.
While the clause “of the same substance” is clearer in plain English, consubstantialis retains a certain stylistic similarity with the Greek. This term emphasized that the Father, the Son, and the Holy Spirit share the same essential being. They are not three gods, nor are they simply made of the same “stuff,” like created things. Instead, they fully share the one divine nature.
IV. English Translations Over Time
“Consubstantial” is less a translation than it is a direct borrowing from Latin. I’m not sure the average English speaker gets any mental image at all when they hear it. “One in being” is similarly cryptic. “Of the same essence” is slightly more accessible but still abstract.
I understand why the translators chose “consubstantial.” It provides continuity with the Western tradition and aims to avoid introducing errors or unintended connotation. Yet it still feels like it lacks something. I’m concerned that something is comprehension among the laity.
If you were to stop ten Christians of any stripe after church and ask them what “consubstantial” means, I really don’t know what you would get. In a profession of faith that unites almost all of historic Christianity, it seems important that this central concept be clear. Not everyone needs to be a theologian, but I can’t help wondering whether the words we use make an already difficult mystery harder to grasp.
Maybe no single English word can fully capture the reality the Council was striving to defend.
V. Theological Significance
CCC §242
Following this apostolic tradition, 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 with the Father.”
CCC §262
The Incarnation of God’s Son reveals that God is the eternal Father and that the Son is consubstantial with the Father, which means that in the Father and with the Father the Son is one and the same God.
There are about nine sections of the Catechism that use the word “consubstantial.” This single concept holds together the core of Trinitarian theology and unites the overwhelming majority of Christians across history. And yet, even with all its authority, it still sounds a little clunky to modern ears.
VI. Conclusion
The history of this one word, consubstantial, shows how much weight the choices of translators can carry. Whether it’s rendered “consubstantial,” “one in being,” or “of the same essence,” the phrase affirms that the Son (with the Holy Spirit) is fully God, equal to the Father, and sharing the same divine nature. This truth stood at the center of the Church’s defense against heresies that would have significantly shifted the Christian understanding of God altogether.
We may not always feel the force of that precision when we recite the Creed on Sundays, but it remains a cornerstone of our faith. In the end, perhaps the very difficulty of this word is an invitation: to dig deeper, to reflect more seriously, and to recognize that some mysteries of faith will always exceed the reach of our simplest language.