A second-century Christian in Alexandria carried a small amulet inscribed with a prayer to the archangel Michael, alongside a charm for protection against demons. A twenty-first-century evangelical in Texas carries a Bible and a cross necklace. Both call themselves Christian. The beliefs that separate them are not merely a matter of time but of a fundamental shift in what Christianity was understood to be.
Old Christianity and new Christianity refer to the transformation of Christian belief from its early, diverse, often esoteric forms to the centralized orthodoxies that dominate today. The key change is the move from a mystical, experiential faith with multiple competing traditions to a doctrinally defined, institutionally controlled religion. That shift did not happen overnight. It took centuries of councils, creeds, and the systematic suppression of alternative voices.
Where Did the Diversity of Early Christianity Go?
The first three centuries of Christianity were a period of extraordinary diversity. Gnostic groups, Marcionites, Ebionites, and proto-orthodox communities all claimed the name. The discovery of the Nag Hammadi library in 1945 revealed texts like the Gospel of Thomas, the Gospel of Philip, and the Apocryphon of John. These present a very different Christ: a revealer of secret knowledge (gnosis) rather than a sacrificial lamb. In the Gospel of Thomas, Jesus says, “If you bring forth what is within you, what you bring forth will save you. If you do not bring forth what is within you, what you do not bring forth will destroy you.” That is not a call to faith in an atoning death. It is a call to self-knowledge.
The Council of Nicaea in 325 CE, convened by Emperor Constantine, began the process of defining orthodoxy. The Nicene Creed established the Trinity as dogma. Subsequent councils at Constantinople (381 CE), Ephesus (431 CE), and Chalcedon (451 CE) further narrowed acceptable belief. The Church Fathers like Irenaeus of Lyons (c. 130-202 CE) wrote against heresies, labeling Gnostic teachings as deviations. Irenaeus’s Against Heresies is a catalog of what he considered false doctrines, but it also preserves the very ideas he sought to destroy.
The result was a canon of scripture that excluded many texts. The New Testament as we know it was not finalized until the late fourth century. Athanasius of Alexandria’s Easter letter of 367 CE listed the 27 books that would become the standard. The texts that did not make the cut were burned, buried, or hidden. The Nag Hammadi codices were buried in the desert, likely by monks who wanted to preserve them. That act of preservation gives us a window into a Christianity that might have been.
How Did the Meaning of the Cross Change?
The cross is the most visible symbol of Christianity, but its meaning shifted dramatically. Early Christians rarely used the cross as a symbol. The ichthys (fish) and the chi-rho monogram were far more common. The cross was a Roman instrument of execution, shameful. Crucifixion was reserved for slaves and rebels. To display a cross in the first century would have been like wearing a miniature electric chair around your neck.
After Constantine’s vision of a cross in the sky before the Battle of the Milvian Bridge in 312 CE, and the Edict of Milan in 313 CE, the cross became a symbol of victory and imperial power. By the fifth century, the crucifix (the cross with the body of Christ) appeared in art. The meaning had inverted: from an instrument of torture to a symbol of triumph. That inversion is a microcosm of the larger shift in Christian belief. The early emphasis on hidden knowledge and personal transformation gave way to a public, political religion.
The Eucharist underwent a similar transformation. Early Christian communities gathered for a communal meal with esoteric overtones. The Gospel of Philip describes the Eucharist as a sacrament of the bridal chamber, a mystical union. By the Middle Ages, the Eucharist had become a ritualized sacrifice performed by priests, with the doctrine of transubstantiation formalized at the Fourth Lateran Council in 1215. The believer’s role shifted from participant to observer.
What Happened to Christian Magic and Mysticism?
Early Christian practice included magic and folk healing. Amulets with biblical verses, exorcisms, and the use of holy water were common. The Greek magical papyri, dating from the second century BCE to the fifth century CE, show Christians invoking angels and even pagan deities. Origen of Alexandria (c. 184-253 CE) wrote about the power of names and theurgic practices. He believed that the name of Jesus could drive out demons, and he defended the use of incantations.
The church gradually suppressed these practices, labeling them superstition. By the Middle Ages, the line between approved miracles and condemned witchcraft was drawn. The Malleus Maleficarum (1487) explicitly condemned the use of Christian symbols in folk magic. The Reformation accelerated this disenchantment. Martin Luther and John Calvin rejected sacramental magic: the idea that a blessed object or ritual could convey grace. For them, faith alone sufficed.
Modern Christianity, especially Protestantism, largely rejects ritual magic. Catholicism and Orthodoxy retain some sacramental magic: blessed objects, relics, holy water. But the enchanted world of early Christianity, where the divine was directly accessible through secret knowledge, has been replaced by a disenchanted world where faith alone is the channel. The loss is not just of practices but of a worldview. The early Christian saw demons in every shadow and angels in every light. The modern Christian sees a natural world governed by laws, with God acting only through providence.
Gnostic vs Orthodox: Two Irreconcilable Visions
The most dramatic comparison is between Gnostic Christianity and orthodox Christianity. Gnostics believed the material world was a mistake created by a lesser god, the Demiurge. Salvation came through knowledge of one’s divine spark, a return to the Pleroma (the fullness of the divine). The orthodox affirmed the goodness of creation and salvation through faith in Christ’s atoning death. The Gnostic Christ was a teacher who revealed hidden truths. The orthodox Christ was a sacrifice who paid the debt of sin.
Another comparison: early Christian mysticism versus modern evangelicalism. The Desert Fathers of the fourth century, such as Anthony the Great (c. 251-356 CE) and Evagrius Ponticus (345-399 CE), sought direct experience of God through asceticism and contemplative prayer. Evagrius developed a system of eight evil thoughts that later became the seven deadly sins. His goal was apatheia, a state of spiritual stillness. Modern evangelicals emphasize a personal relationship with Jesus through scripture and conversion. The contemplative tradition, with its focus on inner transformation and theosis (deification), was largely lost in the West after the Reformation. It survives in Eastern Orthodoxy and in the writings of mystics like Meister Eckhart (c. 1260-1328 CE) and John of the Cross (1542-1591 CE), but it is no longer mainstream.
What People Get Wrong About Early Christianity
The most common misconception is that early Christianity was unified. It was not. The New Testament itself contains competing theologies. Paul’s emphasis on faith versus James’s emphasis on works is the most obvious example. The Gospels themselves differ on key details: the birth of Jesus, the resurrection appearances, the nature of Jesus’s divinity. These differences were not resolved until the canon was fixed.
Another misconception is that Gnosticism was a single movement. It was a diverse set of traditions, from the Valentinians to the Sethians to the Manichaeans. They disagreed on many points, including the nature of the Demiurge and the role of Christ.
A third misconception is that Constantine “invented” Christianity. He did not. He gave it legal status and political power, which changed its character. But the beliefs that became orthodoxy were already present in the second century, championed by figures like Irenaeus and Tertullian (c. 155-220 CE). Constantine accelerated a process already underway.
Finally, many assume the Bible has always been the same book. The canon was debated for centuries. The Muratorian fragment (c. 170 CE) lists most of the New Testament but omits Hebrews, James, and 1 and 2 Peter. The canon was not finalized in the East until the late fourth century. The texts that were excluded, like the Gospel of Thomas and the Gospel of Mary, offer alternative visions of Jesus that challenge the orthodox narrative.
FAQ
What is the difference between Gnostic and orthodox Christianity? Gnostic Christianity taught that salvation comes through secret knowledge (gnosis) of one’s divine origin, while orthodox Christianity taught salvation through faith in Christ’s atoning death and resurrection.
Why were Gnostic texts excluded from the Bible? Church fathers like Irenaeus considered them heretical because they denied the goodness of creation and the full humanity of Jesus. The canon was shaped to reflect the emerging orthodox consensus.
Did early Christians practice magic? Yes. Amulets, exorcisms, and incantations were common. The Greek magical papyri contain Christian prayers and spells. The church later suppressed these practices as superstition.
How did the Council of Nicaea change Christian belief? It established the doctrine of the Trinity and the divinity of Christ as official dogma, marginalizing Arian and other non-Trinitarian views. It also set a precedent for imperial involvement in church doctrine.
The Thread That Connects Old and New
The changes between old and new Christianity are not simply a story of loss. They are a story of how a small, esoteric movement became a world religion. The early Christian who wore an amulet and the modern Christian who wears a cross are both reaching for the same thing: a connection to the divine. The forms have changed, but the impulse remains. For those who want to explore the lost traditions, the Nag Hammadi library is a good place to start. The texts there preserve voices that were silenced but never fully erased. They remind us that Christianity could have been something else.
For further reading, explore our guide to esoteric traditions, the glossary entry on Gnosticism, and our article on the Nag Hammadi library.