Sunday School Review: Basic Church History: Nicaea through the Middle Ages, Part 4

The late 4th and early 5th centuries were a pivotal time for the Christian Church, marked by dynamic theological debates and structural changes that reshaped its identity. Following Constantine's legalization of Christianity in 313 AD, the church had moved from the margins of society to the corridors of imperial power. Yet with this newfound prominence came internal struggles. The Council of Nicaea in 325 AD had formally condemned Arianism, but the theological ripples of the debate over Christ’s nature and relationship to the Father continued to stir the church. Against this backdrop arose influential leaders and controversies that would shape the trajectory of Christianity for centuries.

If you’re new here and missed last week's review, you can find it here.

Ambrose of Milan

Among these towering figures was Ambrose, a Roman governor unexpectedly thrust into the role of bishop in Milan around 374 AD. His elevation was met with acclaim, but also skepticism—Ambrose was not yet baptized when he was chosen. Nevertheless, his subsequent devotion to the Nicene Creed and his firm opposition to Arianism solidified his reputation as one of the church’s foremost defenders of orthodoxy.

Ambrose wielded significant moral authority, confronting Emperor Theodosius I after the massacre at Thessalonica and demanding public penance. This act of defiance exemplified his belief that the church must hold even the most powerful accountable to the authority of Christ. Ambrose also profoundly influenced Augustine, baptizing the young philosopher and setting him on a path that would transform Christian theology.

Augustine of Hippo

If Ambrose represented the church’s moral authority, Augustine of Hippo embodied its intellectual and theological depth. Born in 354 AD, Augustine’s journey to faith was long and winding. His Confessions narrate his restless pursuit of truth, which ultimately led him to embrace Christianity under Ambrose’s guidance.

Augustine’s contributions to the church are monumental. His writings, including City of God and On the Trinity, addressed questions about sin, grace, and salvation. During the Donatist controversy—a schism in North Africa over the validity of sacraments administered by lapsed clergy—Augustine argued that the efficacy of the sacraments rested in Christ, not the moral character of the minister. This insistence on the church’s unity and reliance on God’s grace helped steer Christianity away from fractious legalism.

Jerome

While Augustine wrestled with the intricacies of theology, Jerome devoted his life to ensuring Christians had access to the Word of God. Born in 347 AD, Jerome’s early life was marked by intense scholarly ambition, which he later directed toward the study of Scripture.

His most enduring legacy is the Vulgate, a Latin translation of the Bible commissioned by Pope Damasus I. This translation unified the Western church's scriptural texts and became the foundation for medieval Christianity. Jerome’s rigorous asceticism and sharp wit often placed him at the center of theological controversies, but his commitment to biblical fidelity remained unwavering. His contributions remind us that theology must be rooted in the Word of God, accessible to the people of God.

Pope Leo the Great

Pope Leo I, who assumed the papacy in 440 AD, navigated the church through turbulent waters. While theological debates over Christ’s nature raged, political instability in the Western Roman Empire compounded the church’s challenges. Leo’s leadership at the Council of Chalcedon (451 AD) was decisive.

Leo’s Tome, a theological treatise, articulated the dual nature of Christ—fully God and fully man in one person. This statement became the foundation of the council’s definition of orthodox Christology. Leo’s insistence on the primacy of the Roman bishopric also laid the groundwork for the papacy’s central role in Western Christianity, marking a turning point in the church’s structure and authority.

The Donatist Controversy

While figures like Augustine and Leo grappled with theological nuances, the Donatist controversy exposed the church’s struggle with sin and forgiveness in the wake of persecution. Donatism emerged in North Africa after the Diocletian persecutions, when some Christians, under duress, had renounced their faith. The Donatists argued that clergy who had lapsed could no longer administer valid sacraments, dividing the church.

Augustine’s response emphasized the universality of grace and the centrality of Christ. He reminded the church that its holiness derived from its Head, not its members. This resolution reinforced the church’s unity and upheld the power of forgiveness, ensuring that no human failure could undermine God’s work.

The Rise of the Patriarchal System

As theological controversies simmered, the church’s structure evolved to accommodate its expanding influence. By the late 4th century, five major centers of Christianity—Jerusalem, Antioch, Alexandria, Rome, and Constantinople—had emerged as hubs of ecclesiastical authority. The bishops of these cities, known as patriarchs, wielded significant influence, shaping doctrine and governance.

Constantinople, as the “New Rome,” gained prominence after Emperor Constantine relocated the empire’s capital there in 330 AD. This shift created tensions between the Eastern and Western churches, particularly as the bishops of Constantinople and Rome vied for preeminence. These patriarchal cities became centers of theological innovation and conflict, playing critical roles in the councils that defined orthodoxy.

A Church Steadfast in Christ

Amid these theological and structural shifts, the church’s commitment to the truth of Christ’s person and work remained steadfast. Leaders like Ambrose, Augustine, Jerome, and Leo each contributed to the preservation of orthodoxy, addressing challenges with boldness and faith. The resolution of controversies like Donatism and the rise of patriarchal governance underscored the church’s resilience and unity.

This rich historical tapestry provides the backdrop for the Christological debates that followed. It is to these debates—beginning with the errors of Apollinarius and Nestorius—that we turned, tracing how the church refined its understanding of the Incarnation and preserved the gospel’s truth.

Apollinarius and Apollinarianism

Apollinarius of Laodicea was a well-respected bishop and theologian known for his staunch defense of Christ's divinity against Arianism. However, his attempt to articulate the union between Christ's divine and human natures led to another theological error—what we now call Apollinarianism in his rather dubious honor.

Apollinarius taught that in Jesus Christ, the divine Logos replaced a rational human soul. In his view, Christ had a human body and a "sensitive" soul, but his rational mind was entirely divine. While Apollinarius seemed intent on safeguarding Christ's divinity, his teaching created a problem in the other direction—a functional denial of Christ's true humanity.

The implications of Apollinarianism were significant for the early church. If Christ lacked a fully human mind, how could He represent humanity in His redemptive work? For instance, Hebrews 2:17 insists that Christ had to be made like us "in every respect" to be a faithful high priest and accomplish our salvation. Apollinarius's view of Christ as less than fully human jeopardized this biblical truth.

The First Council of Constantinople (381 AD) not only reiterated Nicaea's condemnation of Arianism; it also condemned Apollinarianism, affirming Christ's full humanity alongside His full divinity. 

Nestorius and Nestorianism

However, in the years following Constantinople, another Christological debate erupted, this time over how to understand the relationship between Christ's divine and human natures. The key figure in this controversy was Nestorius, the bishop of Constantinople.

Like Apollinarius, Nestorius' motivations seemed noble. He sought to safeguard the distinction between Christ's two natures. His intentions were orthodox, but his theology became problematic because he tended to separate Christ's humanity and divinity too much, as though they were two distinct persons loosely connected in one body. Nestorius's critics accused him of teaching that Christ was, in effect, two persons—one human, one divine—united in a single body. This view, later termed Nestorianism, undermined the unity of Christ's person and risked compromising the truth (and admitted mystery) of the Incarnation.

Theotokos and Christotokos

One of the most heated controversies associated with Nestorianism was the use of the term Theotokos ("God-bearer") to describe Mary. This term had long been used in Christian worship and liturgy to affirm that Mary, as the mother of Jesus, gave birth to one who is fully God. For Nestorius, however, the term suggested that Mary was the mother of Christ's divine nature. Therefore, he preferred the term Christotokos ("Christ-bearer"), emphasizing that Mary gave birth to the human nature of Christ.

But for the defenders of orthodox Christology, this was not just a matter of semantics. If Christ is one person, fully God and fully man, then Mary gave birth to that one person, not to a part of Him. By rejecting the term Theotokos, Nestorius appeared to separate Christ's divinity and humanity in a way that threatened the unity of His person.

The Council of Ephesus (431 AD)

The controversy surrounding Nestorius's teaching became so heated that it led to convening the Council of Ephesus in 431 AD. The council, led by Cyril of Alexandria, condemned Nestorius's teachings as heretical. In defending the orthodox position, the council affirmed the full unity of Christ's person. Jesus Christ is one person with two natures, divine and human, fully united without confusion or division. 

The council also upheld the continued use of Theotokos to describe Mary, not to elevate Mary herself but to preserve the truth that the one born of her was truly God incarnate. This affirmation was critical for safeguarding the awe-inspiring reality of the Incarnation: that in Jesus Christ, God became man, not merely united with man.

For those of us in the evangelical tradition, the Council of Ephesus holds great significance. It stands as a key moment in the church's articulation of the mystery of the Incarnation, a doctrine central to the gospel itself. We hold to the truth that Christ must be fully God and man for His redemptive work to be sufficient and effective. 

If Christ were only divine, He could not have truly taken on our humanity to atone for our sins. If He were merely human, He could not bear the infinite weight of God's wrath or mediate between God and man. The Council of Ephesus ensured that the church would continue to confess the glorious mystery of the God-man, the eternal Word, who "became flesh and dwelt among us" (John 1:14).

While we do not venerate Mary as some traditions do, we understand the importance of affirming that the one born of her was the eternal Son of God. Properly understood, the title Theotokos protects the truth of the Incarnation and directs our worship to Christ, not to Mary.

Conclusion

The aftermath of the First Council of Constantinople and the Council of Ephesus demonstrates the early church's diligent defense of the gospel in the face of Christological heresies. Whether confronting Apollinarianism's denial of Christ's full humanity or Nestorianism's division of His person, these councils served to protect the biblical doctrine of the Incarnation. As heirs of the Protestant evangelical tradition, these debates underscore the importance of a robust Christology that preserves the gospel message: that in Christ, God became man so that we might be reconciled to God through Him.

As we look back on these pivotal moments, we're reminded of God's faithfulness in preserving His truth throughout church history. And as we continue to proclaim the gospel, we stand in the line of those early defenders of the faith who refused to compromise on the person and work of Christ. Stand firm, then. Keep the faith.

Resources

Bruce L. Shelley, Church History in Plain Language (Nashville: Thomas Nelson, 1995).

Justo L. González, The Story of Christianity, Vol. 1: The Early Church to the Dawn of the Reformation (New York: HarperCollins, 1984).

B.K. Kuiper, The Church in History (Grand Rapids:L Wm. B. Eerdmans Publishing Company, 2001).

Unless otherwise indicated, all Scripture quotations are from The ESV® Bible (The Holy Bible, English Standard Version®), © 2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.