Previous article in this series: December 1, 2020, p. 112.

We have now explained why the second ecumenical council in Constantinople (381) was necessary. Although the first ecumenical council in Nicea (325) had condemned Arianism (which denied that Christ is God), that heresy continued to hold influence and semi-Arianism (which said that Christ is similar to God, although not God) had developed. Some who opposed Arianism developed other wrong views of Christ. In addition, the question arose how the Holy Spirit related to the Father and Son. To address these matters, Emperor Theodosius I called the Council of Constantinople.



In His perfect timing, God had raised up Theodosius for this purpose. A previous emperor, Julian the Apostate, had favored paganism. Other previous emperors supported Arianism. By contrast, Theodosius defended orthodox Christianity as Nicea had set it forth. One way that he promoted Christianity was by forbidding idolatrous worship and practices. And he was concerned that dissension in the church would undermine the unity of the empire. In short, he called the Council as one who loved the Christian faith, though he was also politically motivated.

In May 381, 186 bishops gathered for this Council. Thirty-six of them denied that the Holy Spirit was God, refused to assent to the Nicene Creed, and were denied a seat at the council. 150 remained—a small number, in comparison to the attendance at other councils. The Council met into July of that year.

All these bishops were from the eastern part of the empire. The pope sent no representatives. Rome would later ratify the main doctrinal decision of the Council and the creed it produced, but would not ratify all of its decisions—especially those that we will examine in the next article.



The Council made four significant decisions, the first of which is the most significant doctrinally. It said: “The faith of the three hundred and eighteen fathers assembled at Nice in Bithynia shall not be set aside, but shall remain firm. And every heresy shall be anathematized, particularly that of the Eunomians or Eudoxians, and that of the Semi-Arians or Pneumatomachi, and that of the Sabellians, and that of the Marcellians, and that of the Photinians, and that of the Apollinarians.”1

The significance of the Council of Constantinople, then, is twofold. First, it decisively established the doctrine of the Trinity. It did so by upholding the decisions of the Council of Nicea, by rejecting Arianism and semi-Arianism, and by asserting that the Holy Spirit is God. The church would continue to grow in her understanding of these doctrines, but what she believed about God as Triune was clear. When heretics later denied the Trinity (think of Michael Servetus, in John Calvin’s day, for instance), the Christian church would have no trouble rejecting these denials as heresy.

Second, the Council began to lay the foundation for a right doctrine of Christ—a correct Christology. Having declared Him to be God, and having rejected Apollinarianism’s denial that Christ had a complete human nature, the Council began leading the church into a right understanding of the person and natures of Jesus Christ. It was only a beginning; the next several ecumenical councils would continue to address this matter. However, the Council of Constantinople made a right beginning.



These doctrinal developments the Council codified in its creed. We commonly call this the “Nicene Creed,” but it could more accurately be called the “Nicene-Constantinopolitan Creed.” The Nicene- Constantinopolitan Creed incorporates the first part of the creed drawn up at Nicea, which set forth the positive statement of the Trinity. However, the version of 381 is distinct from the version of 325 in four ways.

First, the later version adds words and phrases to its confession regarding Christ in order to underscore that Christ is both truly God and truly man. Second, the earlier version led the church to confess faith “in the Holy Spirit” without saying anything more about that aspect of her faith. The version of 381 elaborates on the confession regarding the Holy Spirit, emphasizing that He is divine. Third, the later version adds the confession regarding Christ’s church, the remission of sins, and our hope for the resurrection of the body and life in the world to come. Finally, the later version drops the anathemas found in the version of 325.

This creed is foundational to orthodox Christianity, even as developed in the Reformed faith. The Belgic Confession (Art. 9) indicates that Reformed believers willingly receive what is taught in this creed. This creed is the lasting legacy of the Council of Constantinople and the enduring gift of God to His church of all ages.


1 “Canons” as found in The Nicene and Post-Nicene Fathers, Second Series, Volume 14: The Seven Ecumenical Councils, ed. Philip Schaff (Grand Rapids: Wm. B. Eerdmans, 1988), 172.