Bruce Shelley wrote, “Theology is using our own language and our own way of thinking to explain God’s truth.”[1] This is one reason for the different theological statements in the church; each culture has found a different way of expressing biblical truth to their world.

During the second and third centuries, Christians struggled to communicate the gospel to a changing world. The first generation of Christians were Jews who shared an Old Testament understanding of God and His world. Beginning in the second century, most Christians came from pagan Gentile cultures. These new believers did not share the theological foundation of Jewish converts. During these centuries, Christian theologians struggled to define core Christian beliefs in a way that was both faithful to Scripture and intelligible to their world.

The term orthodoxy means right belief, or right doctrine. Heresy is wrong doctrine, doctrine that contradicts the essential teachings of the Bible. It is important to realize that not every doctrinal disagreement involves heresy. We should apply this term only to teachings that deny the true gospel.

Early Christians knew that external enemies such as Rome were a threat to the church. They soon learned that an even greater danger came from inside, the danger of false teaching. Much of our theological understanding today comes from the church’s response to heresy. When false teachers denied core doctrines of the faith, Christians worked to define biblical teaching in a way that all Christians could understand. The church relied on three sources of authority in responding to heresy: the canon (the collection of inspired Scripture), church leaders (when representing the whole church), and creeds (summaries of orthodox doctrine).

The earliest heresies concerned the nature of Jesus Christ. John’s gospel showed that Jesus is both fully divine and fully human. John wanted his readers to know that Jesus was fully God; “these are written so that you may believe that Jesus is the Christ, the Son of God….”[2] He also wanted his readers to know that Jesus was fully human; he pointed to the blood that flowed from Jesus’ side on the cross, the nail prints in Jesus’ hands, and Jesus’ hunger.

While some early heresies denied Jesus’ deity,[3] the most common heresies denied his humanity. These heretics denied the reality of the Incarnation; they said that Jesus only appeared to be man.

Gnosticism

One of the most dangerous heresies in the early church was Gnosticism. Gnosticism was based on a philosophy that taught that the world is divided between two forces, good and evil.[4] Borrowing from ancient Greek philosophers like Plato, Gnostics taught that only the spiritual world is pure; everything physical is corrupt. Although some Gnostics claimed to be Christians, their teachings contradicted the essential truths of the Christian faith.

First, the Gnostics claimed that salvation comes through secret knowledge.[5] Gnostics taught that this special knowledge transported their followers to a purely spiritual realm which was no longer limited by the material world, and that provided a special relationship to a God who was too perfect to be known in a physical world. This contradicted the biblical teaching that salvation is available to all people - by grace through faith in Jesus Christ.[6] Rather than secret knowledge, the knowledge necessary to salvation is found through the Bible.

Second, because they believed that the physical world is evil, Gnostics taught that the God of the Old Testament was an evil god who created the material world, while the Jesus of the New Testament was a spiritual being. According to this teaching, an “unknowable God” who had nothing to do with the physical universe was the true God. The God of the Old Testament was an evil God who created the world and kept humans in bondage to matter. This God prevents mankind from returning to the spirit world. Deliverance from the physical world is available only through the secret knowledge of the Gnostics.

This teaching contradicted the teaching of Genesis 1 that the world God created was “good.” It contradicted the biblical teaching that God is holy. And it contradicted the teaching of John 1:1-3 that Jesus is God and that “all things were made through him.”

Third, Gnostics denied the truth of John 1:14, “The Word became flesh and dwelt among us.” There were two forms of Gnosticism – both of which contradicted John 1.

One form of Gnosticism said that Jesus was divine and that he only appeared to have a human form. This form of Gnosticism taught that Jesus was only spirit. This teaching denied the reality of the incarnation. It denied the full humanity of Jesus Christ.

A second form of Gnosticism said that Jesus was an ordinary person who was filled with the divine spirit at baptism. This divine spirit departed before the crucifixion. This teaching denied the full deity of Jesus Christ.

Either form of the Gnostic heresy denied a biblical doctrine of the atonement. The atonement required that Jesus be truly God and truly human. As the sacrifice for our sin, Jesus suffered a real physical death on the cross. To be a substitute for man, Jesus had to be man.[7] Gnosticism denied the reality of the atonement.

The New Testament writers reacted strongly against the false teaching of Gnosticism. In Colossians, Paul condemned those who practiced asceticism, claimed superior knowledge, and denied the resurrection. He bluntly warned Timothy, “Avoid the irreverent babble and contradictions of what is falsely called ‘knowledge.’”[8]

John responded to those who denied Jesus’ humanity, “That which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands….”[9] He assured his readers that Jesus was truly human. Later, he warned that any spirit that does not confess Jesus “is not from God. This is the spirit of the antichrist.”[10]

Several “Gnostic Gospels” were written in the second century. These writings, such as “The Gospel of Thomas,” “The Gospel of Mary,” “Acts of Peter,” and “Acts of Thomas” were known and rejected by the early church fathers. They were never accepted as part of the New Testament canon.

► The ideas of Gnosticism have become popular in the early twenty-first century. Writers have returned to the idea that secret knowledge was hidden by the early church. Some of the Gnostic Gospels are taught in universities. Are Gnostic ideas affecting the society in which you minister? If so, which ones?

Docetism

One of the most influential Gnostic groups was led by Marcion, the son of a wealthy church elder. In A.D. 140, Marcion was excommunicated from his father’s church for false doctrine and immoral behavior. Marcion went to Rome where no one knew of his past. He made a large donation to the church in Rome, joined the church, and soon began to teach a heretical doctrine that combined Gnosticism and Christianity.

Marcion’s teaching said that the God of the Old Testament was a wrathful God, not the father of Jesus. Marcion said that the father of Jesus was a higher God of grace and love. He taught that the Old Testament was not a sacred book. Another part of Marcion’s heresy is called Docetism, which means that Jesus only seemed to be human. This teaching denied the reality of the Incarnation. Like other Gnostics, Marcion believed that physical matter was evil. Because of this, he could not accept that a holy God would take on human form.

When the church in Rome recognized Marcion’s heresy, they removed him from the church’s fellowship. He then planted heretical churches in Italy and Asia Minor.

Modalism

Modalism denies the biblical doctrine of the Trinity. It denies that the three persons of the Trinity coexist eternally. Instead, modalism teaches that God is one person who has revealed himself in three forms (or modes).

According to modalism, God manifested himself in the mode of the Father in the Old Testament. In the incarnation, He manifested himself in the mode of the Son. After the ascension, He is manifested to the church in the mode of the Holy Spirit. Modalism teaches that the Father, Son, and Holy Spirit do not exist at the same time. This denies the New Testament teaching of the Trinity.[11]

In the third century, Tertullian, from North Africa, defended orthodoxy against modalism. Because of his clear explanations, Tertullian is called the “Father of Latin Theology.” To explain the nature of the Trinity, Tertullian used the phrase “one substance, three persons.” This showed that God is truly three persons, not simply three forms of one person.

Tertullian also helped Christians to understand the mystery of the incarnation by describing Jesus as “one person and two substances.” In one person, Jesus was both fully divine and fully human.

Early Heresies
Gnosticism	Salvation based on secret knowledge. All physical matter is evil. Denies the reality of the incarnation.
Docetism	Jesus only appeared to be human.
Modalism	Denies the doctrine of the Trinity.

…From Then to Now…

Occasionally, someone claims to discover an ancient text that contradicts the Bible. Recent discoveries include Gnostic gospels such as the “Gospel of Thomas” and the “Gospel of Judas.” Each time, skeptics proclaim, “This discovery proves that the New Testament story of Jesus is false.” However, these discoveries are not new.

In the first century, Paul wrote that Hymenaeus and Alexander had “shipwrecked” their faith. These men were teaching a false doctrine of “myths” and “speculations” rather than teaching the gospel of faith. [12] Late in the first century, Ignatius of Antioch wrote seven letters in which he argued against the heresies that would later be known as Gnosticism.

False books such as the Gospel of Thomas were known and rejected in the second century. Christians who lived soon after the events of the Gospels knew these false stories; but more importantly, they knew the true gospel. In the second century, Justin Martyr, Irenaeus, and Tertullian all referred to these Gnostic teachings. They knew that these writings were false.

Do not let false gospels shake your confidence. Jude warned that, “In the last time there will be scoffers, following their own ungodly passions. It is these who cause divisions, worldly people, devoid of the Spirit.” The Christian response is simple: “Build yourselves up in the faith, pray in the Holy Spirit, keep yourselves in the love of God, and save those who doubt.”[13] The “Gnostic gospels” are not new. They are old heresies in new packages. The gospel is still the only good news![14]

Response to Heresy: The Canon

When Marcion denied the incarnation and the authority of the Old Testament, he was faced with a problem: the four Gospels clearly taught Jesus’ humanity and other New Testament books referred to the Old Testament books that Marcion rejected. His solution was simple: accept only the books that agreed with him! It was a short list: part of Luke (omitting the story of Jesus’ birth) and ten of the Pauline epistles.

To show that Marcion’s message was not biblical, it was necessary to agree on the question, “Which sacred books are truly the Word of God?” Marcion’s false teaching inspired the church to establish a New Testament canon.

The term “canon” means measuring stick or standard of measurement. The biblical “canon” refers to the books inspired by God. The church asked three questions:

Is it apostolic? Is this book connected to an apostle?[15]
Is it universal? Do churches from all areas of the known world accept this book?
Is it consistent? Does this book agree with what we know about God from the Old Testament? The Word of God will not contradict itself.

The early church fathers did not create our Bible; the church fathers simply recognized the biblical books that had been inspired by the Holy Spirit. Just as the Holy Spirit inspired the writing of Scripture, the Spirit supervised the selection of the canon.

By A.D. 190, the Muratorian Canon included most of our present New Testament. This list was not complete, and it includes two books that were later rejected. However, the Muratorian Canon shows that the majority of the canon was accepted in the second century. The canon was finalized by the fourth century. In A.D. 367, Bishop Athanasius from Alexandria wrote an Easter letter that contained a complete list of New Testament books. In A.D. 393 and 397, church councils at Hippo and Carthage confirmed the same canon.

The false teaching of Marcion showed the necessity of defining the canon. The New Prophet movement led by Montanus showed the necessity of closing the canon. In the middle of the second century, the church was in need of revival. The enthusiasm of the early church was fading; some Christians lived little differently than the world. As the church tried to evangelize the pagan culture, some Christians began to think and act like the pagan world.

In A.D. 160, Montanus, a Christian from Asia Minor (modern day Turkey) began to call the church to a return to discipline and a renewed emphasis on the Holy Spirit. If the message of Montanus had been only a call to separation from the world, self-discipline, and openness to the leadership of the Holy Spirit, he could have inspired genuine revival. However, he and two female “prophetesses” (Prisca and Maximilla) began making prophesies and falling into a state of ecstasy in which they claimed that the Holy Spirit spoke through them. Montanus and his followers became known as the “New Prophets.”

Two problems arose with the Montanists:

The New Prophets made false predictions. Based on Deuteronomy 18:20-22, it became clear that the Holy Spirit was not the source for their prophecies.
The demands of the New Prophets exceeded the moral standards of the Bible. Like the Gnostics, the Montanists banned marriage. They required extreme fasts and ascetic practices in preparation for the return of Jesus.

Some churches considered Montanus to be a heretic like Marcion; others refused to call him a heretic.[16] However, the church as a whole rejected the teachings of Montanus and his followers. The New Prophets’ claim of new revelation gave another motivation for the creation of a New Testament canon. By “closing the canon” (on the basis that no further apostolic books could be written), the church prevented men like Montanus from putting personal prophecies above Scripture.

The church rejected the false claims of Montanus and his followers. It did not reject the work of the Holy Spirit. Instead, the church recognized the difference between the Spirit’s work in the first century and later centuries. In the Apostolic period, the Holy Spirit inspired the writing of Scripture; “men spoke from God as they were carried along by the Holy Spirit.”[17] In later times, the Holy Spirit illuminated Scripture to the minds of readers; “When the Spirit of truth comes, he will guide you into all the truth.”[18]

The New Testament Canon Is…
Apostolic: Each book was written by an apostle or associate of an apostle.
Universal: Each book was accepted throughout the entire Christian church.
Consistent: No book contradicts earlier biblical revelation.
Closed: No new books will be added to the canon.

Response to Heresy: Church Order

In his letters, Paul wrote about the offices of deacon, overseer, and elder.[19] These officers provided leadership for the local churches. Churches usually met in private homes, and there was little organizational structure beyond the local church.

In the second and third centuries, churches became more highly organized. Instead of meeting in private homes, congregations began to build church buildings. A bishop (sometimes called overseer) supervised all the churches in a city, and elders were appointed for each local church. The bishops became known as “popes” (Latin for “fathers”).[20] They were responsible to guide the church to faithful obedience to Scripture. Controversies such as the fight over Gnosticism gave greater control to the bishops, because they were seen as the final authority in matters of doctrine.

From the perspective of later history, we see both the benefit and the danger of this increased authority. The benefit is the preservation of orthodoxy against the attacks of heretics. Irenaeus wrote, “The tradition of the apostles is protected by the successions of elders.”[21] He believed that the truth of the gospel could best be protected by the bishops and church leaders. When false teachers such as Arius gained popularity in the fourth century, orthodox bishops such as Athanasius defeated his heretical teaching.

However, there is danger when any human being is given unlimited power. Bishops were given power to decide doctrinal disputes; they were given power to forgive sins; they were considered the mediators between laymen and God. This went far beyond the role of bishops and elders in the New Testament church.

Since the Reformation, there have been three views regarding the authority of bishops.

Some “back to the Bible” movements insist that the church today should return to the model of the apostolic church. This provides a system of elders for each local church, but no denominational structure beyond the local church.
Some Christians argue that church structure must change to meet the needs of each new generation. They say that the model of Acts was appropriate for the first century church but is not a model for today.
Roman Catholic and Eastern Orthodox leaders teach that the authority of the bishops was guided by the Holy Spirit and is permanently binding for the church.

Response to Heresy: The Creeds[23]

A third response to heresies such as Gnosticism and Docetism was to carefully define Christian doctrine for new converts. New Testament statements such as “Jesus is Lord” and “God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory” are apostolic summaries of Christian belief.[22] These statements may have been part of the baptismal liturgy in the first century.

After the conflict with Marcion, Christian leaders began to ask more detailed questions of baptismal candidates to ensure that they understood the essential doctrines of the Christian faith. These statements of faith became known as the “Rule of Faith” or a “Creed.” The most common creed used today is the Apostles’ Creed, which first appeared as a baptismal confession in second century Rome.

Another summary of early Christian beliefs was the symbol of the fish. The Greek word for fish was ἰχθύς (ichthus). Each letter reminded early Christians of some aspect of belief about Jesus of Nazareth. The fish symbol became a simple “creed” for early Christians: Jesus Christ, God’s Son and our Savior.

[24]

ἰ = Iesous (Jesus)
χ = Christos (Christ)
θ = Theou (God’s)
ύ = Uios (Son)
ς = Soter (Savior)

[1] Bruce L. Shelley, Church History in Plain Language, 3rd ed. (USA: Thomas Nelson, 2008), 48

[2] John 20:31

[3] The most common of these was a group known as the Ebionites. They taught that Jesus was a mere man who became the Messiah through careful obedience to the Law.

[4] This philosophy is called dualism.

[5] The word “gnostic” comes from a Greek word, gnosis, meaning “to know.”

[6] Ephesians 2:8-9

[7] Hebrews 2:14-17

[8] 1 Timothy 6:20

[9] 1 John 1:1

[10] 1 John 4:3

[11] The reality of the Trinity (three persons acting simultaneously) is seen in scriptures such as Matthew 3:16-17. At the baptism of Jesus, all three persons of the Trinity were involved. The Son was baptized by John, the Spirit descended like a dove, and the Father spoke from heaven saying, “This is my beloved Son, with whom I am well pleased.”

[12] 1 Timothy 1:3-7, 20

[13] Jude 1:18-22

[14] If you want to study more about a biblical answer to these false gospels, you can read Darrell L. Bock, The Missing Gospels (Nashville: Thomas Nelson Books, 2006).

[15] Most New Testament books were written by apostles. The exceptions are books that are closely related to apostles: Mark traveled with Peter and recorded his memories; Luke traveled with Paul; Timothy was a disciple of Paul; James and Jude were half-brothers of Jesus and were accepted with the apostles.

[16] Even Tertullian, a defender of orthodox theology, became a follower of Montanus. He was attracted to Montanus’ emphasis on revival and self-discipline.

[17] 2 Peter 1:21

[18] John 16:13

[19] 1 Timothy 3:1-13; 5:19

[20] Eventually the pope of the church in Rome was considered the highest authority in the Roman Catholic Church. This pope claimed authority over the bishops of local churches.

[21] Quoted in Timothy Paul Jones, Christian History Made Easy (CA: Rose Publishing, 2009), 28

[22] Philippians 2:11 and 1 Timothy 3:16

[23]"Do you believe in Christ Jesus, God’s Son, who was born by the Holy Spirit through the virgin Mary, was crucified under Pontius Pilate, died and was buried, and rose again on the third day, alive from the dead, and ascended into heaven, sat at the Father’s right hand, and will come again to judge the living and the dead? Do you believe in the Holy Spirit, the holy church, and the resurrection of the flesh?”
- An early form of the Apostle’s Creed

[24]Image: "ICTHUS", retrieved from https://commons.wikimedia.org/wiki/File:ICTHUS.gif, public domain.