The Church in This Era

In the year 313 the Emperor Constantine, by the Edict of Milan, granted toleration to the Christian faith, and within a generation the church that had prayed in catacombs found itself summoned to imperial palaces. The age of the martyrs gave way to the age of the councils. This shift, accomplished within a single lifetime, was so sudden that the church scarcely had time to take its bearings. Bishops who remembered the persecution under Diocletian now received the favor, and the meddling, of emperors.

The period from the Council of Nicaea (325) to the Council of Chalcedon (451) is the age of the four great ecumenical councils. In it the church wrestled to confess, in language faithful to Scripture, two truths that lie at the heart of the gospel: who God is, and who Christ is. The first half of the era settled the doctrine of the Trinity; the second half settled the doctrine of the person of Christ. Meanwhile, in the Latin West, a converted rhetorician named Augustine of Hippo was forging the doctrines of sin and grace that would shape Western Christianity for a thousand years and would be recovered by the Reformers.

This was an imperial church, and that fact cut both ways. Emperors convened councils, paid for the travel of bishops, and enforced their decrees. Sometimes imperial power served orthodoxy; often it served heresy, for an Arianizing emperor could exile a faithful bishop as easily as a pious one could restore him. The church learned, painfully, that truth is not settled by majorities or by thrones, but it also learned to use the gifts of providence without bowing to them.

Where We Are in the Story

We stand at the hinge between the apostolic and patristic foundations and the long medieval development. The previous era gave us the canon, the rule of faith, and the early apologists and martyrs. Now the church, freed from persecution, turns inward to its own confession and discovers that the deepest threats are not from Caesar but from teachers within who would dissolve the very deity of the Son or the integrity of the Savior’s person.

What is settled here is not negotiable later. When the Reformers recovered the gospel in the sixteenth century, they did not overturn Nicaea or Chalcedon; they received them with gratitude as faithful summaries of Scripture. The Westminster Confession assumes the Trinitarian and Christological grammar hammered out in these councils (WCF 2, WCF 8). This is the era in which the church learned to say what it had always believed.

Key Figures

Arius (c. 256–336), the Alexandrian presbyter whose denial of the Son’s full deity provoked the first great council.

Alexander and then Athanasius of Alexandria, defenders of the eternal Son; Athanasius would stand “against the world” through five exiles.

Constantine, who convened Nicaea, and his successors, whose theology swung between orthodoxy and Arianism for two generations.

The Cappadocian Fathers — Basil of Caesarea, Gregory of Nazianzus, and Gregory of Nyssa — who gave the Trinity its enduring grammar: one ousia in three hypostases.

Cyril of Alexandria and Nestorius, antagonists over the unity of Christ’s person.

Pope Leo the Great, whose Tome shaped the Chalcedonian Definition.

Augustine of Hippo (354–430), bishop, theologian of grace, opponent of Pelagius and the Donatists, the towering mind of the Latin West.

Key Controversies and Developments

Three great struggles define the age. The first was Trinitarian: was the Son truly God, of the same substance as the Father, or a creature, however exalted? Arius said the Son was made; Nicaea said he was begotten, not made. The controversy was not closed in 325 but raged for half a century until Constantinople (381) secured both the Son’s deity and, against the Pneumatomachi, the Spirit’s.

The second was Christological: granting that the Son is fully God, how is he also fully man, and how do the two natures unite in one person? Nestorius seemed to divide the person into two; Eutyches confused the natures into one. Ephesus (431) and Chalcedon (451) charted the narrow channel between them.

The third, in the West, was soteriological and ecclesiological: Augustine against Pelagius on sin and grace, and against the Donatists on the nature of the church. These Western debates would prove decisive for the Reformation.

Councils, Creeds, and Confessions

• Nicaea (325): the original Nicene Creed; homoousios; condemnation of Arius.
• Constantinople (381): the Niceno-Constantinopolitan Creed (the “Nicene Creed” we recite); the deity of the Holy Spirit.
• Ephesus (431): affirmation of Theotokos; condemnation of Nestorianism.
• Chalcedon (451): the Chalcedonian Definition; two natures in one person.
• Carthage (418) and Orange (529): condemnation of Pelagianism and Semi-Pelagianism.

What Was Settled — and What Was Left

Settled: the full and eternal deity of the Son and the Spirit, hence the doctrine of the Trinity; the full deity and full humanity of Christ united without confusion or division in one person; the bondage of the fallen will and the necessity of sovereign grace. These are the church’s permanent treasures.

Left unsettled, or settled only in seed: the precise relation of grace and human response (Orange leaned Augustinian but stopped short of double predestination); the nature of the church’s holiness and the sacraments; the relation of church and empire. The East and West would also drift apart, the filioque clause becoming one fault line.

A Reformed Assessment

We receive the ecumenical creeds with thanksgiving as faithful, Scripture-tested summaries of the faith (WCF 1.10). They are not a second source of authority but the church’s confession of the one Word. Nicaea and Chalcedon stand because they say what Scripture says, and the Reformed churches confess them without reserve.

At the same time we read this history under sola Scriptura and semper reformanda. We honor Athanasius and the Cappadocians as instruments of providence, yet we note that even faithful councils could err and contradict one another (WCF 31.4), so that creeds bind only insofar as they conform to the Word. Augustine’s recovery of grace was a gift not fully appropriated until the Reformation, when the church returned to the Scriptures and found there the sovereign grace Augustine had glimpsed.

Lessons for the Church Today

First, doctrine matters, and precision in doctrine is not pedantry but love for Christ. A single letter — the iota in homoousios versus homoiousios — marked the boundary between the gospel and a counterfeit. Second, faithfulness is often a minority report; Athanasius stood nearly alone. Third, the church must use the language of its age to confess the unchanging truth, neither despising tradition nor enthroning it above the Word.

Further Reading

• Athanasius, On the Incarnation of the Word.
• The Nicene and Chalcedonian creeds (in any good collection, e.g., Schaff’s Creeds of Christendom).
• J. N. D. Kelly, Early Christian Doctrines.
• Leonard Hodgson and later, more accessibly, Robert Letham, The Holy Trinity: In Scripture, History, Theology, and Worship.
• Augustine, Confessions and the anti-Pelagian writings.