Church History — Unit 3: Heresies, Councils, and Imperial Christianity

For three centuries the church had asked one question above all others: how do we survive Rome? Then almost overnight, between 312 and 313, that question vanished and was replaced by one almost no one had thought to prepare for: how do we survive Rome's friendship?

Constantine's victory at the Milvian Bridge in October 312 changed everything. The Edict of Milan in 313 granted Christians freedom of worship, restored confiscated property, and ended the era in which Christians could be subjected to periodic and sometimes empire-wide imperial persecution. Within a generation Christianity would be the favored religion of the empire. Bishops who had hidden in caves now sat in conference with the emperor. Buildings that had been illegal now rose as basilicas at imperial expense. The blood of the martyrs had become the seed of an established church.

This was the right answer to a three-hundred-year prayer, and a problem the church had never had to solve. Unit 3 is the story of how the church wrestled the new questions through the fourth and early fifth centuries, defined her doctrine of God and Christ in the four great ecumenical councils, and produced — while she was at it — the second great century of preaching in her history.

Constantine was a soldier and politician, not a theologian. The night before the Milvian Bridge, according to his biographer Eusebius, he saw a sign in the sky — a cross of light with the words "In this sign conquer." He marked his soldiers' shields with the Christian Chi-Rho, won the battle, and attributed the victory to the Christian God. From that day forward Constantine considered himself a patron of the church, though he was not actually baptized until just before his death in 337.

His policy was simple: support, protect, unify. He returned confiscated property, gave clergy tax exemptions, commissioned new church buildings, summoned bishops to imperial conferences. He expected the church to be one church, not feuding factions. The first major test came almost immediately, in North Africa, in the Donatist controversy.

During Diocletian's persecution some North African bishops had handed over the Scriptures to be burned rather than face death. They were called traditores — "those who have handed over." After persecution ended, a man named Caecilian was consecrated bishop of Carthage by another bishop accused of having been a traditor. A rigorist faction refused to accept the consecration. They argued that any sacrament administered by a fallen bishop — baptism, ordination, communion — was invalid. They elected their own bishop, Donatus, and the Donatist church began.

The mainstream church, defended most powerfully by Augustine a century later, took a different position: the validity of the sacrament depends on Christ, not on the worthiness of the minister. A baptism is a baptism even when performed by an unworthy bishop, because it is Christ who does the baptizing, not the bishop's hands. This principle — the sacrament is ex opere operato, "from the work performed," rather than dependent on the minister's holiness — would shape Western theology for the next thousand years. The Donatist controversy is a permanent warning against confusing the church's purity with the worthiness of her ministers.

The Donatist controversy was about the church. The Arian controversy was about Christ Himself, and it was the most serious theological crisis the church had ever faced. The Arian crisis nearly split the empire, occupied four ecumenical councils, and forced the church to put into precise language what it had always confessed: that Jesus Christ is fully and truly God.

The trouble began around 318 in Alexandria. A presbyter named Arius was teaching publicly that the Son was not eternal. Arius reasoned: the Father is unbegotten, eternal, without beginning. The Son is begotten of the Father, which means the Son had a beginning. "There was when He was not." The Son is the highest of God's creatures, the first and most exalted of all created beings, but He is still a creature. He is not, properly speaking, God. He is not co-eternal with the Father.

Arius's argument had a certain crispness. He was a popular preacher, a clever rhetorician, and he wrote his theology in catchy songs that spread through the docks of Alexandria. By the early 320s the controversy was disrupting the entire eastern church. Constantine was alarmed. He had supported Christianity in part to provide unity for his empire, and now Christians were dividing over a question he could not entirely follow. He decided to call a council. Every bishop in the empire would be invited, fed at imperial expense, and they would settle the question once and for all in the imperial city of Nicaea, in the summer of 325.

About 318 bishops attended Nicaea — the number is traditional. Many bore the scars of Diocletian's persecution: missing eyes, severed limbs, ruined hands. They were not theological abstractions. They were men who had bled for the name of Jesus Christ. Now they were being asked to put into a single Greek word what that name meant. The word they chose was homoousios — of the same substance. The Son is not like the Father (homoiousios, with one extra letter). The Son is of the same substance as the Father — fully God, eternally God, equal to the Father in deity.

The original Nicene Creed: "We believe in one God, the Father Almighty… And in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father… God of God, Light of Light, true God of true God, begotten not made, of the same substance as the Father…" Almost every clause was aimed at Arius. Begotten not made — against the Arian claim that the Son was created. Of the same substance — the homoousios. True God of true God — reversing Arius's claim that the Son was God only in a derivative sense. The creed concluded with anathemas: "Those who say there was when He was not… the Catholic Church anathematizes." Three hundred and sixteen bishops signed. Two refused and were exiled with Arius. Constantine considered the matter settled. It was not.

The fifty years after Nicaea were chaos. Different emperors took different sides. Synods met in different cities and issued different creeds. Arian and semi-Arian formulas multiplied. Jerome later said, "The whole world groaned and marveled to find itself Arian." The Nicene confession nearly went under. It survived because of one man.

Athanasius was about thirty years old at Nicaea, a young deacon serving as secretary to his bishop Alexander. Three years later he became bishop of Alexandria himself. For the next forty-five years he defended the Nicene confession against successive Arian and semi-Arian emperors, was exiled five times to four different countries, returned five times, and outlived nearly every one of his enemies. The Latin phrase Athanasius contra mundum — "Athanasius against the world" — captures both his isolation and his stubbornness. When the empire was Arian, Athanasius was Nicene. When his fellow bishops compromised, Athanasius would not.

His major works include On the Incarnation, written when he was barely in his twenties — one of the masterpieces of Christian theology, arguing that only a Christ who was fully God could save fully human beings, and only a Christ who was fully man could heal humanity. He wrote Four Discourses Against the Arians, the great anti-Arian polemic. And he gave the church a final gift in his Easter letter of 367: the first known list of the twenty-seven New Testament books we still receive as canonical, in the order we still use. Athanasius did not invent the canon — the church had been recognizing these books for centuries — but his Easter letter formally closed the canon question Marcion had raised two centuries earlier.

Athanasius did not live to see his vindication. He died in 373. Eight years later, at the Council of Constantinople in 381, the Nicene confession was reaffirmed and expanded, and Arianism was finally crushed within the empire.

Three friends from the Roman province of Cappadocia (modern central Turkey) finished what Athanasius had begun. They are called the Cappadocian Fathers. Basil the Great (c. 330–379) was bishop of Caesarea, wrote a monastic rule that still governs Eastern Orthodox monasticism, built hospitals and schools at Caesarea that pioneered organized Christian charity, and wrote a treatise On the Holy Spirit defending the Spirit's full deity. Gregory of Nazianzus (c. 329–389), Basil's lifelong friend, earned the title the Theologian — given by the Eastern church only to him, the apostle John, and Symeon the New Theologian. His Five Theological Orations are masterpieces of patristic preaching. Gregory of Nyssa (c. 335–395) was Basil's younger brother and a more philosophical mind — sometimes called the philosopher of the Cappadocians.

The Cappadocians gave the church the formula that has held the doctrine of the Trinity steady for sixteen centuries: one ousia (substance) in three hypostases (persons). One God in three Persons. Father, Son, and Holy Spirit, equal in essence, distinct in person. The Council of Constantinople in 381 took this formula, expanded the Nicene Creed to confess the full deity of the Spirit, and gave the church the creed she still recites every Lord's Day.

The Trinity had been settled by 381. The doctrine of Christ's person had not. If the Son is fully God and fully man, how do those two natures relate in the one Person of Jesus? Two more councils answered.

The Council of Ephesus in 431: Nestorius of Constantinople had been preaching that the divine Son and the human Jesus were so distinct that Mary should not be called theotokos (God-bearer). She was the mother of the man Jesus only, Nestorius said. Cyril of Alexandria and the council fiercely disagreed. The one who was born of Mary was the one Person, fully divine and fully human. To split him into two persons was to lose the Christ of the gospel. The council condemned Nestorianism and affirmed Mary as theotokos — not because Mary is divine, but because the One she carried truly was God incarnate.

The Council of Chalcedon in 451, perhaps the most important Christological statement the church has ever produced, faced the opposite error: Monophysitism, which taught that Christ had only one nature, the divine swallowing the human. Chalcedon rejected this and gave the church its definitive Christological formula: Jesus Christ is one Person in two natures, fully God and fully man, the two natures united without confusion, without change, without division, without separation. The Chalcedonian Definition has been the standard of orthodox Christology ever since.

By 451 the church had her doctrine of God (Father, Son, and Holy Spirit, one in essence, three in person) and her doctrine of Christ (one Person, fully God and fully man, two natures unconfused). The first four ecumenical councils — Nicaea 325, Constantinople 381, Ephesus 431, Chalcedon 451 — together produced the orthodox confession of the catholic faith.

First, doctrine is not optional. Arius was not a bad man with bad theology. He was a popular preacher with a logical-sounding argument. The church survived him only because she had bishops who knew exactly which word, in which language, would hold the line.

Second, councils define what every pulpit must defend. When you preach Christ as fully God and fully man this Sunday, you are preaching Nicaea and Chalcedon. Honor the line. Stand on it.

Third, the validity of the gospel does not depend on the worthiness of the preacher. The Donatist controversy taught the church a hard lesson: the sacrament is from Christ, not from the minister. This protects every congregation from the moral collapse of any pastor and every preacher from the unbearable weight of being the source of his own message.

Fourth, the second great century of preaching was the century of expository preaching through whole books. Chrysostom did not bounce from topical sermon to topical sermon. He preached through Genesis, then through Matthew, then through the Pauline corpus. Whole books. Verse by verse. Sunday by Sunday. The book-by-book pattern Chrysostom modeled has been the bedrock of every great preaching ministry since.

By 451, when the bishops adjourned at Chalcedon, the Roman Empire that had once been Christianity's persecutor and was now her patron was beginning to crumble. The western half would not survive the fifth century. In 410, Visigoths under Alaric sacked Rome itself for the first time in eight hundred years. The shock was so great that Augustine of Hippo would spend the last decade of his life writing The City of God to explain what had happened.

And the church would not die with the empire. The doctrines hammered out at Nicaea, Constantinople, Ephesus, and Chalcedon would carry the gospel intact through the centuries of barbarian darkness that came next. The expository preaching modeled by Chrysostom and Ambrose would become the heartbeat of monastic communities preserving the faith through the collapse. Pass this examination, and we will meet the most important figure of the next thousand years: Augustine of Hippo, the man who watched Rome fall and explained it in light of eternity. Unit 4 awaits.