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Are Catholics Christian? What about the Eastern Orthodox? And the Protestants? These are the three major sects of Christianity, but they are certainly not the only ones. What are the defining beliefs that separate “Christian” from “non-Christian?” Since the 4th century, the Nicene-Constantinopolitan Creed has been the litmus test for Christian belief. The goals of this article are: (1) to provide some historical background to this important Creed, and (2) to make clear some of the foundational tenants of the Creed (note the emphasis on ‘some’ and ‘foundational).

Historical Background

Peter’s sermon at Pentecost in Acts 2 presents the Gospel (i.e., Good News) of Jesus Christ:

“Men of Israel, hear these words: Jesus of Nazareth, a man attested to you by God with mighty works and wonders and signs that God did through him in your midst, as you yourselves know—this Jesus, delivered up according to the definite plan and foreknowledge of God, you crucified and killed by the hands of lawless men. God raised him up, loosing the pangs of death, because it was not possible for him to be held by it. […]

This Jesus God raised up, and of that we all are witnesses.  Being therefore exalted at the right hand of God, and having received from the Father the promise of the Holy Spirit, he has poured out this that you yourselves are seeing and hearing. […]

Now when they heard this they were cut to the heart, and said to Peter and the rest of the apostles, “Brothers, what shall we do?” And Peter said to them, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit. For the promise is for you and for your children and for all who are far off, everyone whom the Lord our God calls to himself.”

Acts 2:22-24, 32-33, 37-39 (ESV)

From the time of the Apostles onward, this was the message preached by Christians. However, an important question arose: how is Jesus¹, God? Is he fully God, or is he half-God? After all, according to the birth account in Luke 1, Jesus is the Son of God—and the son of Mary, a human. The ancient Greco-Roman context of the early Christians was filled with myths of half-gods (i.e. people who were half-god and half-human). So is Jesus a half-god/half-man, like Hercules? These sorts of questions began to take shape over the first three centuries of Christianity. A definitive answer came at the end of the fourth century at the Council of Constantinople (381 AD). But before diving into the answers, let’s take a look at what preceded.

Arius’ False Claims and the Council of Nicea

The story begins with Arius of Alexandria. He claimed that there was ‘once when the Son was not’—that is, that there was a time when the Son of God did not exist. Because God is eternal, Arius’ claim that the Son of God was not eternal meant that the Son of God was less God than the Father. This claim was quite controversial, and lead to the Council of Nicaea in 325 AD during which Arius was condemned as a heretic. The church leaders who gathered in Nicaea determined that Arius’ claim was outside the bounds of Scripture.

During this council, they wrote the Nicene Creed as a clarification of Christian belief. One key point the church stated was that the Son of God is homoousios with the Father. This term, homoousios, is made up of ‘homo,’ meaning ‘same,’ and ‘ousia,’ which means substance. Thus, the church stated that the Son of God is of the same substance as God the Father.

Alas, this did not fully resolve the issue.

Continued Disagreements about God

Despite the unity against Arius displayed at the Council of Nicaea, in the aftermath of the council the leaders of the Church remained divided, as they were not yet in agreement about what “homoousios” meant. This term, which the Arians could not use (hence, in part, its utilization in the creed), needed further clarification. In the wake of the Council of Nicaea, three theological camps emerged, with respective leaders:

  • Homoousian: Those who believed the Son of God and God the Father shared the one, exact same substance. That is, there is only one substance, which both have.
    • Leaders: Athanasius of Alexandria, Basil of Caesarea, Gregory of Nazianzus
  • Homoian (‘homoi’ means ‘like’): Those who believe the Son of God was ‘like’ God the Father. They did not wish to use the language of ‘ousia,’ or ‘substance.’
    • Leaders: Basil of Ancyra, Eustathius of Sebaste
  • Heteroousian (‘hetero’ means ‘different’): Those who believe the Son of God was ‘of a different substance’ from the Father. These followers were the heirs of Arius’ theology, who developed it to its final form.
    • Leaders: Aetius and Eunomius of Cyzicus

Between the Council of Nicaea (325) and the Council of Constantinople (381), many smaller councils were convened by the various theological camps, and the pendulum of opinion swayed between the three. The church found itself in theological turmoil, as it did not have a unified understanding about the Son of God. Fortunately, this turmoil found resolution at the Council of Constantinople (381). The Homoousian camp won out as being most theologically accurate. This final resolution, which has remained the standard of Christian belief since its issuance, is known as the Nicene-Constantinopolitan Creed (today, it is commonly shortened to the Nicene Creed).

The Nicene-Constantinopolitan Creed

The Nicene-Constantinopolitan is a statement of belief intended for all those who call themselves “Christian.” It is full of complex, philosophical thought: every word, phrase, and line matters. Let’s explore some of them together.

We believe in one God,
the Father, the Almighty,
maker of heaven and earth,
of all that is, seen and unseen.

We believe in one Lord, Jesus Christ,
the only Son of God,
eternally begotten of the Father,
God from God, Light from Light,
true God from true God,
begotten, not made,
of one Being with the Father.
Through him all things were made.
For us and for our salvation
he came down from heaven:
by the power of the Holy Spirit
he became incarnate from the Virgin Mary,
and was made man.
For our sake he was crucified under Pontius Pilate;
he suffered death and was buried.
On the third day he rose again
in accordance with the Scriptures;
he ascended into heaven
and is seated at the right hand of the Father.

He will come again in glory to judge the living and the dead,
and his kingdom will have no end.

We believe in the Holy Spirit, the Lord, the giver of life,
who proceeds from the Father and the Son.
With the Father and the Son he is worshiped and glorified.
He has spoken through the Prophets.
We believe in one holy catholic and apostolic Church.
We acknowledge one baptism for the forgiveness of sins.
We look for the resurrection of the dead,
and the life of the world to come. Amen.

English translation from the Book of Common Prayer, 1979 edition.

Structure of the Creed

The Creed may be broken up into four key parts: three parts concerning God, and one part concerning the church. The three parts on God reflect the Christian belief in God as Trinity, that is, the belief that God is both THREE and ONE. There are not three Gods, but one God. And yet, the one God is also three. This is a complicated theological and philosophical concept, and will be taken up more fully in another post (click to be notified when those are released). However, it is helpful to know that Christians believe that the Father, Son, and Holy Spirit are each fully God—but there is only one God who is Father, Son, Holy Spirit.

Explanation of Each Part of the Creed

Part 1: “We believe in one God, the Father, the Almighty, maker of heaven and earth, of all that is, seen and unseen.”

Christians believe that there is only one God. There are not multiple gods. There is one God. This God is the Father almighty, who created all things which exist (“all that is”). Nothing exists apart from God, for God makes all things and brings them into existence.

Part 2: “We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father…of one being with the Father.”

Christians believe that there is one Lord. That Lord is Jesus Christ. Jesus Christ is “the only Son of God,” who is “eternally begotten of the Father.” Christians believe that God has a Son, and that this Son exists eternally. There was never a time when the Son of God did not exist. This is what is meant by ‘eternally begotten.’ The Son of God eternally comes forth from the Father. Furthermore, the Son of God is homoousios (translated above as “of one being”) with the Father, meaning that the Father and Son share the one, exact same substance. The Son of God is not of a “different” substance or simply “like” the Father (as the heteroousians and homoians claimed, respectively).

Moreover, Christians hold that all things were made through the Son of God (a reaffirmation of God as one: the Father creates all things through the Son).

Furthermore, this Son of God was born to the virgin Mary. That is, the eternal Son of God was made man in the act of his birth. Jesus Christ—the incarnate Son of God—was crucified and died (“He was crucified under Pontius Pilate; He suffered death and was buried.”). Christians believe that Jesus Christ was killed; He experienced death, and descended to the dead. However, the glorious news which Christians proclaim is that three days after his death, Jesus Christ literally resurrected from the dead.

After His resurrection, Jesus ascended into heaven to take his place at the right hand of the Father. Christians believe that Jesus will return a second time. When Jesus returns, He will come to judge the living and the dead. Moreover, Jesus will rule as king, seated on His heavenly throne for all eternity.

Part 3: “We believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father and the Son. With the Father and the Son he is worshipped and glorified.”

Christians believe in the Holy Spirit—the third person of the Trinity. That the Holy Spirit is “the Lord the giver of life” attests once more to the Christian belief that there is only one God, who is three—God is Trinity. As the Father is the creator of all, it is through the Son that all things are made, and the Holy Spirit that gives life. God is Father, Son, Holy Spirit. God is triune: three and one.

Part 4: “We believe in one holy, catholic, and apostolic church.”

Christians believe that there is one church.

The church is holy—that is, set apart for God.

The church is catholic—that is, universal. (Note: ‘catholic’ means universal. In the context of the creed, ‘catholic’ does not mean Roman Catholic).

The church is apostolic—that is, the church was founded by the apostles, and traces itself back to the apostles of Jesus.

The church acknowledges that there is only one baptism for the forgiveness of sins. That is, a person may only be baptized once for the forgiveness of their sins. (Note: this does not mean that people are only forgiven their sins once, and that they can never be forgiven again. We are sinners saved by grace, and we confess our sins and repent every time we sin, knowing that Jesus is faithful to forgive us our sins.)

Finally, Christians believe that there will be a literal resurrection of the dead; this resurrection signifies Jesus’s return and the end of this present age. Christians await eagerly “the life of the world to come,” that is, eternal life in the kingdom of God.

What does all this mean for today?

Roman Catholics, Eastern Orthodox, and a large number (but not all) of Protestants continue to recognize the Nicene-Constantinopolitan Creed as the standard for correct Christian belief. In theory, all those who call themselves “Christian” ought to hold to each of the beliefs outlined in the Creed. Historically, anyone who rejected the beliefs outlined in the Creed was considered outside the Christian faith. Hence, the Creed has remained a ‘measuring stick’ declaring the essentials of Christian belief for over 1600 years. However, there are certainly a number of self-identified Christians who would not hold to each and every tenet laid out above.

As noted in the preface to this piece, there are many concepts in the creed not expounded upon in this article (we’d need to write long books to do that). This article focuses more broadly on the historical background and basic tenets of Christian belief, as seen in the Nicene-Constantinopolitan Creed. While not every point was touched upon, I pray I have related here the key foundational pillars, even if I have not engaged with the equally significant finer points of theological doctrine which are necessary in order to articulate the faith in its fullest form.

Keep an eye out for future articles on the Creed, where more of these issues will be addressed (subscribe here to not miss them). Meanwhile, thoughts and questions are encouraged! Please drop a comment or question below. We would love to hear from you!

Recommended Resources for Further Reading

  1. The Trinitarian Controversy – trans./ed. By William G. Rusch
    • A collection of significant primary source documents relating to the historical development of the Nicene Constantinopolitan Creed.
  2. Nicaea and Its Legacy: An Approach to Fourth-Century Trinitarian Theology — By Lewis Ayres
    • Presently the foundational work on fourth-century Trinitarian theology and its developments. Any serious student of Trinitarian thought ought to read this.
  3. The Third Theological Oration, “On the Son” — By St. Gregory of Nazianzus
    • A crucial primary source written by a leader of the Homoousian All five theological Orations are important and worth reading, but this one is particularly significant.
  4. A number of pieces by St. Athanasius; really anything involving “Arians”
    • Athanasius was a wonderful theologian, and a key member involved in the Arian controversy of the fourth century.

¹Important note on language: Christians (myself included) frequently use the terms “Jesus” and “Son of God” interchangeably. However, there is an important distinction in how these words are used in doctrines, especially those discussed below. For the purpose of this article, and in keeping with good theological practice, I use “Jesus” to refer to the man from Nazareth who was born, crucified, died, and rose again. I use “Son of God” to refer to the eternal second person of the Trinity.

About the Author:

Gareth Leake graduated with a Master of Theological Studies from Emory University. His research focused upon fourth-century Trinitarian theology.