top of page

I Believe: A Guide to the Nicene Creed (Part IV)

Theodosius appointing Gregory of Nazianzus as Patriarch in 380 AD. Scene from the 9th century Paris Gregory, an illuminated manuscript of the Homilies of Gregory of Nazianzus.



The First Council of Constantinople, convened in the year 381 AD, was a pivotal event in the history of early Christianity. This ecumenical council, the second of its kind after the First Council of Nicaea in 325 AD, was summoned to address pressing theological controversies and to establish a statement of faith that would further clarify and expand upon the Nicene Creed. In this essay, we will explore the need for the First Council of Constantinople, the theological developments that emerged from it, and the profound implications it had for both the Eastern and Western branches of Christianity.

The Need for the First Council of Constantinople

To understand the need for the First Council of Constantinople, one must first appreciate the historical and theological context in which it took place. The First Council of Nicaea, convened under the authority of Emperor Constantine the Great, had already addressed significant theological disputes. It resulted in the formulation of the Nicene Creed, which primarily aimed to combat the Arian heresy, which denied the divinity of Christ. However, in the decades that followed, new theological challenges emerged that necessitated further clarification.

Theological controversies of the time included disputes over the nature of the Holy Spirit, the relationship between the Father, the Son, and the Holy Spirit (the doctrine of the Trinity), and questions surrounding the personhood of Christ. Some theologians and bishops held diverse and sometimes contradictory beliefs, leading to confusion and division within the Christian community.

Emperor Theodosius I, who reigned from 379 to 395 AD, played a significant role in convening the First Council of Constantinople. Unlike his predecessors, Theodosius was a staunch supporter of Nicene Christianity and sought to establish religious unity within the Roman Empire. His edicts against heresies and his commitment to orthodox Christianity laid the foundation for the council.

Another key figure in the lead-up to the council was Patriarch Gregory of Nazianzus, a prominent theologian known for his defense of Nicene orthodoxy. Gregory's influence and advocacy for the council's convocation were crucial in addressing the theological controversies of the time.

Theological Developments in the Nicene-Constantinopolitan Creed

The primary task of the First Council of Constantinople was to expand upon and clarify the Nicene Creed. The Nicene Creed had been the product of the First Council of Nicaea, but it primarily addressed the divinity of Christ. The Council of Constantinople aimed to provide a more comprehensive statement of faith that would address the nature of the Holy Spirit and further articulate the doctrine of the Trinity.

The Cappadocian Fathers, including Basil the Great, Gregory of Nazianzus, and Gregory of Nyssa, played a crucial role in shaping the theological formulations of the Nicene-Constantinopolitan Creed. These theologians contributed to the understanding of the Trinity, emphasizing the consubstantiality (homoousios) of the Father, the Son, and the Holy Spirit. Their work helped shape the creed's language and concepts.

One of the central theological developments in the Nicene-Constantinopolitan Creed was the articulation of the doctrine of the Holy Spirit. The creed affirmed the divinity of the Holy Spirit and clarified the Holy Spirit's role in the life of the Trinity. This was a response to various pneumatological controversies of the time.

The Nicene-Constantinopolitan Creed exhibited a remarkable degree of theological precision. It sought to eliminate ambiguity and doctrinal confusion by providing clear definitions and affirmations regarding the nature of God, the relationship between the divine persons, and the unity of the Godhead.

Implications for the Eastern and Western Churches

The First Council of Constantinople had significant implications for the Eastern Church, particularly in the Eastern Roman Empire (Byzantium). It helped solidify the orthodoxy of the Nicene Creed and established the theological framework that would guide Eastern Christian thought for centuries.

The council's affirmation of Nicene orthodoxy bolstered the position of Nicene Christianity in the East. It provided a theological foundation for resisting Arianism and other heterodox beliefs, contributing to the eventual triumph of Nicene theology in the Eastern Church.

The Nicene-Constantinopolitan Creed became a foundational document for Eastern Orthodox theology. It shaped theological discussions, influenced the writings of theologians such as John Chrysostom and Cyril of Alexandria, and played a central role in the development of Eastern Christian doctrine.

While the First Council of Constantinople had a more immediate and profound impact on the Eastern Church, it also influenced the Western Church, albeit to a lesser extent.

The Nicene-Constantinopolitan Creed eventually influenced the Western Nicene Creed, albeit with some variations. The Filioque controversy, which centered on the addition of the phrase "and the Son" (Filioque) to the Western Creed's description of the Holy Spirit's procession, would later become a point of contention between the Eastern and Western Churches.

The First Council of Constantinople set a precedent for future ecumenical councils. It demonstrated the importance of addressing theological disputes through ecumenical gatherings and established a model for creedal development that would be followed in subsequent councils, including the Council of Chalcedon in 451 AD.


The First Council of Constantinople was a critical event in the history of early Christianity. It addressed the pressing theological controversies of its time, expanded upon the Nicene Creed, and had profound implications for both the Eastern and Western branches of Christianity. Through the efforts of key figures like Emperor Theodosius I, Patriarch Gregory of Nazianzus, and the Cappadocian Fathers, the council solidified Nicene orthodoxy, clarified the doctrine of the Holy Spirit, and provided a theological framework that would shape the development of Christian thought for centuries to come. The Nicene-Constantinopolitan Creed remains a lasting testament to the theological precision and doctrinal clarity achieved at this ecumenical council, and its impact on Christian theology and practice endures to the present day.


bottom of page