Church History

Why Study Church History?

The doctrines we have studied throughout this course did not arrive fully formed. They were hammered out over centuries, through debate, controversy, persecution, and prayer, by real men and women who took the stakes of theology seriously. To study church history is to understand why the Church believes what it believes, and to stand in the long line of those who have passed the faith on before us.

G.K. Chesterton once described tradition as "the democracy of the dead," giving a vote to those who came before us, not just those alive today. The councils and creeds of the early church are not dusty relics. They are the hard-won conclusions of the Church's most careful thinking about Jesus, God, and salvation, conclusions that still define orthodox Christianity today.

The Early Church (AD 30–313)

Birth and Rapid Growth

The church was born at Pentecost (Acts 2) with approximately 120 believers gathered in Jerusalem. Within a single generation it had spread across the Roman Empire, through Asia Minor, Greece, North Africa, and Rome itself. This explosive growth happened without political protection, institutional infrastructure, or social respectability. It grew through proclamation, community, and the willingness of ordinary people to suffer for their convictions.

The earliest Christians were not seen as a new religion. They were viewed as a Jewish sect that had gone strange. They worshipped a man executed as a criminal, claimed He had risen from the dead, refused to sacrifice to Roman gods, and called a Jewish carpenter "Lord," a title reserved for Caesar. This made them immediately suspicious to both Jewish authorities and Roman rulers.

Persecution

For the first three centuries, Christianity existed under the constant threat of persecution. The Roman Empire periodically launched organized campaigns to suppress the church, demanding Christians renounce their faith, hand over Scripture, or offer sacrifice to the emperor as a god. Those who refused faced imprisonment, torture, exile, or death.

Ten major Roman persecutions are traditionally identified, under emperors including Nero (who blamed Christians for the Great Fire of Rome in AD 64), Domitian, Trajan, Marcus Aurelius, Decius, Valerian, and Diocletian, whose persecution (303–313) was the most severe and systematic. Christians were called to hand over their Scriptures (traditores: "those who hand over," the root of our word "traitor"). Those who refused were called martyrs: from the Greek word for "witness." Their willingness to die rather than deny Christ was one of the most powerful testimonies to the truth of the resurrection.

Constantine and the Edict of Milan (AD 313)

Everything changed in AD 313 when Emperor Constantine issued the Edict of Milan, granting religious tolerance throughout the Roman Empire and specifically ending the persecution of Christians. Constantine claimed to have converted to Christianity after seeing a vision before the Battle of Milvian Bridge (312), reportedly a cross in the sky with the words in hoc signo vinces: "In this sign, conquer."

The effects were dramatic and complex. Christianity went from persecuted minority to the favored religion of the empire almost overnight. Churches were built. Bishops gained political influence. The faith was no longer costly in the way it had been. This opened enormous opportunities for the gospel, and introduced new temptations and complications the church wrestled with for centuries. Constantine also convened the first major ecumenical council, not purely as a spiritual act, but because theological unity served his interest in political unity. This entanglement of church and state set patterns that would shape Christian history for a thousand years.

The Seven Ecumenical Councils

An ecumenical council (from the Greek oikoumene, "the whole inhabited world") is a gathering of church bishops from across Christendom to address doctrinal disputes and establish authoritative teaching. Seven councils are recognized as ecumenical by both Eastern Orthodox and Roman Catholic churches; most Protestant churches affirm the first four as the most foundational for Trinitarian and Christological orthodoxy.

1. First Council of Nicaea (AD 325)

Location: Nicaea (modern-day İznik, Turkey)  |  Called by: Emperor Constantine  |  Central controversy: Arianism

The Problem: Arianism. A presbyter named Arius taught that the Son of God was the Father's greatest creation, divine but still a creature with a beginning. His slogan: "There was a time when He was not." Jesus, on this view, was divine in some sense, but not truly, eternally God. Arianism was popular because it made the Trinity easier to understand by simply making the Son less than the Father.

The Response: The council, led in part by the young deacon Athanasius, rejected Arianism decisively. The key declaration: the Son is homoousios, of the same substance as the Father. Not similar substance (homoiousios), but identical in divine essence. Jesus is not a lesser god or created being. He is fully, truly, eternally God. The council also established a uniform date for Easter and began the Nicene Creed.

2. First Council of Constantinople (AD 381)

Location: Constantinople  |  Called by: Emperor Theodosius I  |  Central controversy: Pneumatomachi ("Spirit-fighters")

Even after Nicaea settled the Son's divinity, a group called the Pneumatomachi denied the full divinity of the Holy Spirit, treating Him as a created, subordinate being. The council affirmed the Spirit's full divinity and personhood, adding to the Nicene Creed that the Spirit is "the Lord, the giver of life, who proceeds from the Father, who with the Father and the Son is worshiped and glorified." This completed the Trinitarian confession and gave us the Nicene Creed in essentially its current form, the most widely used creed in Christian history.

3. Council of Ephesus (AD 431)

Location: Ephesus  |  Called by: Emperor Theodosius II  |  Central controversy: Nestorianism

Nestorius, Archbishop of Constantinople, taught that Jesus had two distinct persons, divine and human, loosely united. He objected to calling Mary Theotokos ("God-bearer"), preferring Christotokos ("Christ-bearer"), since he believed Mary only bore the human Christ, not God Himself. The council, led by Cyril of Alexandria, affirmed that Jesus is one person, not two. Mary is rightly called Theotokos not because she is divine, but because she bore the one person who is fully God and fully man. Nestorianism was condemned.

4. Council of Chalcedon (AD 451)

Location: Chalcedon  |  Called by: Emperor Marcian  |  Central controversy: Eutychianism / Monophysitism

Eutyches overreacted to Nestorianism by teaching that after the incarnation, Jesus had only one nature, the humanity absorbed into the divinity. This is Monophysitism (one nature). The council's response, the Chalcedonian Definition, is one of the most precise doctrinal statements in church history. Christ is declared "perfect in Godhead and also perfect in manhood; truly God and truly man... to be acknowledged in two natures, inconfusedly, unchangeably, indivisibly, inseparably."

The four adverbs are the heart of it. Christ's two natures exist without confusion (not blended, contra Eutyches), without change (neither nature becomes the other), without division (not two persons, contra Nestorius), and without separation (always united in one person). This is the hypostatic union: one person, two complete natures.

5–7. The Later Councils

Second Council of Constantinople (AD 553): Addressed lingering Nestorian tendencies; reaffirmed Chalcedon.

Third Council of Constantinople (AD 680–681): Addressed Monothelitism: the view that Christ has two natures but only one will. The council affirmed that Christ has two wills (divine and human), perfectly united and without conflict.

Second Council of Nicaea (AD 787): Addressed the Iconoclast Controversy: whether images (icons) of Christ and saints could be used in worship. The council affirmed the veneration (not worship) of icons. This remains a point of difference between Eastern Christianity and most Western Protestantism.

The Major Creeds

A creed comes from the Latin credo: "I believe." Creeds are brief, authoritative summaries of the core content of the Christian faith, designed to be memorized, publicly confessed, and used to distinguish orthodox belief from heresy. They are not Scripture, but careful summaries of what Scripture teaches.

The Apostles' Creed (c. 2nd–4th century)

Origin: Despite its name, the Apostles' Creed was not written by the apostles. It developed gradually from early baptismal confessions, short statements of faith recited by candidates for baptism. The current form was established by the 4th century. Legend incorrectly held that each of the twelve apostles contributed one article.

Purpose: Originally a baptismal creed, recited by new believers at baptism as a public declaration of faith. It remains widely used today as a summary all traditions can affirm together.

Structure: Organized around the three persons of the Trinity: the Father (Creator), the Son (birth, death, resurrection, ascension, return), and the Holy Spirit (the church, forgiveness, resurrection of the body, eternal life).

The phrase "descended into hell": One of the most debated lines. Interpretations include: Christ experienced the full depth of death and separation; He proclaimed victory to imprisoned spirits (1 Peter 3:18–20); or "hell" refers simply to the realm of the dead (Sheol/Hades), affirming that Jesus truly died. Many Protestant churches omit or reword this phrase.

The Nicene Creed (AD 325/381)

Origin: Produced at Nicaea (325) and expanded at Constantinople (381), written specifically to refute Arianism, to make unmistakably clear that the Son is fully and truly God.

Purpose: The most widely used creed in Christendom, affirmed by Roman Catholic, Eastern Orthodox, and most Protestant churches. The ecumenical creed of the universal church. Where the Apostles' Creed is a personal baptismal confession ("I believe"), the Nicene Creed is the church's corporate doctrinal statement ("We believe").

Key content: The Son is "of one Being with the Father" (homoousios), eternally begotten, not created. The Holy Spirit "proceeds from the Father" and is "worshiped and glorified" with Father and Son. The church is "one, holy, catholic [universal], and apostolic." There will be a resurrection of the dead and life in the age to come.

The Filioque controversy: The Western church added filioque ("and the Son") so the Spirit "proceeds from the Father and the Son." The Eastern church rejected this as an unauthorized addition. This dispute was a major factor in the Great Schism of 1054, which divided Eastern Orthodoxy from Roman Catholicism, a split that has never been healed.

The Chalcedonian Definition (AD 451)

Not a creed in the traditional sense, but a doctrinal definition that functions as the standard of Christological orthodoxy across all major Christian traditions. Its "four withouts" (without confusion, without change, without division, without separation) remain the definitive framework for understanding the person of Christ. See the Council of Chalcedon section above for full treatment.

The Athanasian Creed (c. 5th century)

Origin: Named for Athanasius but almost certainly not written by him. Composed in the Latin West in the 5th century. Athanasius' name was attached because its theology so closely reflects his lifelong defense of Nicene orthodoxy.

Purpose: The most detailed and theologically precise of the three major creeds, dealing extensively with both the Trinity and the person of Christ. Contains strong "damnatory clauses" declaring that those who do not hold its teaching cannot be saved, which has made some churches reluctant to use it in worship.

Key content: An extended defense of Trinitarian theology (one God, three co-equal persons) and Christology (one person, two natures). Insists that neither the unity of God nor the distinction of persons can be compromised.

Key Figures in Early Church History

Athanasius of Alexandria (c. 296–373): The great defender of Nicene orthodoxy. Athanasius contra mundum: "Athanasius against the world." After Nicaea, Arianism made a political comeback and Athanasius was exiled five times by emperors sympathetic to the Arians. He never recanted. The church would not have the Nicene faith without him.

Arius (c. 250–336): The Alexandrian presbyter whose teaching sparked the Arian controversy. Condemned at Nicaea, but his theology persisted and even flourished politically for decades after the council.

Cyril of Alexandria (c. 376–444): Led the opposition to Nestorianism at Ephesus. A fierce defender of the unity of Christ's person, crucial for the church's Christological confession.

Augustine of Hippo (354–430): One of the most influential theologians in Christian history. His works shaped Western thinking on sin, grace, predestination, and the church. His Confessions is one of the greatest spiritual autobiographies ever written.

The Cappadocian Fathers (late 4th century): Basil of Caesarea, Gregory of Nyssa, and Gregory of Nazianzus clarified the distinction between ousia (divine essence, one) and hypostasis (person, three), giving the church the vocabulary needed to confess the Trinity without either tritheism or modalism.

Major Early Heresies at a Glance

Arianism: The Son is the Father's greatest creation, not eternal God. Condemned at Nicaea (325).

Docetism: Jesus only appeared to be human (Greek dokein, "to seem"). Purely divine, no real flesh. Denied in the writings of John and Ignatius of Antioch.

Gnosticism: The material world is evil, created by a lesser god; salvation is through secret spiritual knowledge (gnosis). Irenaeus and Tertullian wrote extensively against it.

Modalism (Sabellianism): God is one person who reveals Himself in three successive modes: first as Father, then Son, then Spirit. Denies the genuine distinction and co-eternity of the three persons.

Nestorianism: Jesus is two persons (divine and human) loosely united. Condemned at Ephesus (431).

Eutychianism / Monophysitism: Jesus has only one nature, the human absorbed into the divine. Condemned at Chalcedon (451).

Pelagianism: Humans can choose good without divine grace; original sin is not inherited but imitated. Condemned at Carthage (418).

Timeline of the Early Church

Key Vocabulary

Key Scriptures

• Acts 2:1–47
• Acts 8:1–4
• John 1:1–14
• John 10:30
• Colossians 1:15–20
• Hebrews 1:1–4
• 1 Peter 3:15
• Jude 3