What Did Early Christians Actually Believe?

Every Christian tradition claims to be the one that best represents “the early church.” Catholics point to apostolic succession and the papacy. The Orthodox claim unbroken continuity with the church fathers. Protestants argue they recovered the original gospel that had been buried under centuries of tradition. Pentecostals say they restored the Spirit-filled worship of Acts 2.

They can’t all be right. But they might all be wrong — or at least oversimplifying — because “the early church” was never the unified, doctrinally settled institution any of these claims require.

The First Two Centuries: Diversity Was the Norm

The Christianity of the first and second centuries looked nothing like what any modern denomination practices. There was no New Testament canon (the books weren’t officially listed until the 4th century). There was no creed. There was no standardized liturgy, no centralized authority, and no agreed-upon theology of the Trinity, the atonement, or the end times.

It is worth being precise here, because the point is often blurred. The Trinity as a formal doctrine — the very word, together with homoousios (“one essence”) and the formula of one essence in three coequal persons — is a post-biblical development. It was worked out over the second through fourth centuries and fixed at the Council of Nicaea in 325 and the Council of Constantinople in 381. The New Testament never states it in those terms. This does not by itself settle whether the doctrine is a faithful drawing-out of scripture or a later overlay — that is exactly what the later parties disputed, and Trinitarians have long argued that the raw materials are already present in the apostolic writings — but the chronology of the formula is not in question.

What there was: a loose network of communities scattered across the Roman Empire, each with its own traditions, its own leaders, and its own understanding of who Jesus was and what his death and resurrection meant.

What Did They Believe About Jesus?

Here’s where it gets interesting. The earliest Christians held a range of views about Jesus’s identity — views that would later be sorted into “orthodox” and “heretical” categories, but which coexisted in the early church without clear boundaries.

Some texts speak of Jesus in exalted, even cosmic terms. The Gospel of John (written around 90–100 AD) opens with the famous line: “In the beginning was the Word, and the Word was with God, and the Word was God.” Hymnic passages such as Philippians 2:6-11 and Colossians 1:15-20 describe Christ in similarly lofty language. Trinitarians read these as describing a pre-existent, fully divine Christ: the Word who “was God” and through whom “all things were made” (John 1:1-3), the one who was “in the form of God” (Philippians 2:6) and “before all things” and in whom “the fullness of God was pleased to dwell” (Colossians 1:17-19). On this reading the New Testament already identifies Jesus with the God of Israel, and the later creeds only made that identification precise. Biblical unitarians read the same passages differently — as the language of God’s plan and wisdom, and of a genuinely human Messiah whom God raised, exalted, and appointed Lord over all creation, to be honoured even as the Father is honoured (John 5:23, Philippians 2:9-11, Acts 2:36) — not as describing a second divine being. Both sides have argued their case from these texts for centuries; neither reading is simply the obvious one.

Some emphasised a human whom God elevated. The Gospel of Mark — the earliest Gospel, written around 65–70 AD — begins not with a cosmic prologue but with Jesus’s baptism, where a voice from heaven declares “You are my Son.” Read on its own, this resonates with Adoptionism: God chose Jesus and elevated him at the baptism. Paul’s letter to the Romans (1:4) says Jesus was “declared to be the Son of God… by his resurrection from the dead” — language some read as implying Jesus became the Son in a new sense at the resurrection, rather than always having been so. Others counter that “declared” marks a public vindication of a sonship Paul elsewhere treats as prior to the resurrection.

Some believed Jesus only appeared to be human. Docetism — the view that Jesus’s body was an illusion — was widespread enough that the author of 1 John felt compelled to address it directly: “Every spirit that confesses that Jesus Christ has come in the flesh is from God” (1 John 4:2). You don’t refute a position nobody holds.

Some believed Jesus was an angel or a cosmic intermediary. Jewish Christianity, particularly in its earliest Palestinian form, may have understood Jesus through the lens of Jewish angel traditions — a divine agent, exalted above all others, but not identical with God in the way Nicaea would later assert.

These weren’t fringe groups on the margins. They were communities of sincere believers reading the same Scriptures and reaching different conclusions. The diversity is visible within the New Testament itself.

The Weight of What Is Missing

Any honest reconstruction also has to reckon with silence. If the eternal pre-existence of the Son, his equality with the Father, and the threefold nature of the one God were the fundamental, saving truths the later creeds made them, it is striking how little the New Testament writers say of them directly. The word “Trinity” never appears. God is never called “three in one.” The Son is nowhere stated in plain terms to be coequal or coeternal with the Father — and his pre-existence rests on a handful of contested texts (John 1:1; John 8:58; Philippians 2:6; Colossians 1:15-17) rather than on any clear statement of doctrine. For a reader trying to recover what the first Christians actually believed, that absence carries weight: it is fair to wonder why apostles writing precisely to teach and correct young churches would leave the single most important truth about God himself almost entirely unstated.

There are two honest ways to read the silence, and the New Testament does not adjudicate between them. Trinitarians answer that the first Christians lived the reality before they had the vocabulary for it — that they worshipped Jesus, baptised in his name, and received the Spirit as God, and that the creeds only later drew out what their practice and their highest Christological language already implied; a truth can be confessed in worship long before it is defined in argument. Biblical Unitarians and many critical scholars answer that the simpler explanation is the obvious one — that the apostles did not teach the Trinity because they did not hold it. They were Jewish monotheists for whom the Father alone was “the only true God” (John 17:3) and Jesus his exalted human Messiah and Lord (Acts 2:36). The silence does not by itself settle the question. But it is a real part of the evidence, and it weighs against the claim that the developed doctrine is simply the plain teaching of the New Testament.

The Canon Was Open

Modern Christians treat the 27-book New Testament as a given. But for the first three centuries, there was no official list.

Churches in different regions used different collections. The Gospel of Thomas was read in some communities. The Shepherd of Hermas was widely popular and nearly made the cut. The book of Revelation was disputed — many Eastern churches rejected it well into the 4th century. Some churches used the Didache (a first-century manual of Christian practice) as Scripture. Others used the Epistle of Barnabas.

The first known list matching our current New Testament comes from Athanasius’s Easter Letter in 367 AD — over three centuries after Jesus. And even after that, churches disagreed. The Ethiopian Orthodox Church has 81 books in its canon. The Syriac churches had a different count. The process of canonization was gradual, contested, and shaped by the same political dynamics that shaped the creeds.

When Did “Trinity” Language Appear?

The Greek word trias and its Latin equivalent trinitas did appear early — but it is important not to read the later doctrine back into the first writers to use them. Theophilus of Antioch (around 180 AD) is usually credited with the earliest surviving use of trias, and Tertullian (around 200 AD) with the earliest use of trinitas. In both cases the words name a threesome or triad — Father, Son, and Spirit grouped together — rather than the developed metaphysics of one essence in three coequal persons.

The earliest writers who used this vocabulary were characteristically subordinationist: they spoke of the Son and the Spirit as in some way derived from, and ranked beneath, the Father. The coequal, one-essence understanding that the word “Trinity” later came to carry was the outcome of the fourth-century debates, not the meaning these earlier authors had in mind. Trinitarians and their critics part ways over what to make of this: defenders of the doctrine see the early triadic groupings as the seed from which the mature confession legitimately grew, while unitarian readers see the later coequality as a genuine change rather than a clarification. What is not disputed is that the continuity lies in the word, while the doctrine carried by it developed considerably.

Orthodoxy and Heresy: A Retrospective Distinction

The traditional narrative says orthodoxy came first — the apostles taught the true faith, and heresies were deviations from it. The historian Walter Bauer challenged this in 1934 with his landmark work Orthodoxy and Heresy in Earliest Christianity. Bauer argued that in many regions, what was later called “heresy” was actually the original form of Christianity, and “orthodoxy” was a later import from Rome.

Bauer’s thesis has been critiqued and refined, but its core insight remains widely accepted among historians: the clean line between “orthodoxy” and “heresy” is largely a product of the 4th century. Before Constantine, before the councils, before the creeds, Christianity was a family of related movements with significant theological diversity.

The historian Bart Ehrman, building on Bauer, has argued in works like Lost Christianities that the Christianity we know today is the version that won — not necessarily the version that was original or universal.

What They Agreed On

This isn’t to say early Christians agreed on nothing. Across the diversity, certain convictions were remarkably consistent:

Jesus was Lord. However they understood his metaphysical nature, early Christians confessed Jesus as kyrios — Lord — a title that carried echoes of the divine name in the Greek Old Testament. (How much weight that echo should bear is itself one of the disputed points between Trinitarian and unitarian readers.)

Jesus had been raised from the dead. The resurrection was the non-negotiable claim. Paul says it explicitly: “If Christ has not been raised, your faith is futile” (1 Corinthians 15:17).

The coming kingdom. Early Christians expected Jesus to return and establish God’s reign. The ethical urgency of the early church — radical sharing, care for the poor, willingness to die — was fueled by this expectation.

Love as the supreme ethic. Paul’s “greatest of these is love” (1 Corinthians 13), John’s “God is love” (1 John 4:8), Jesus’s commandment to love enemies (Matthew 5:44) — across every strain of early Christianity, love was central.

Baptism and a shared meal. The specific theology varied, but the practices were universal.

What They Didn’t Agree On

The metaphysics of the Trinity. The precise mechanism of salvation. The canon of Scripture. The role of Jewish law for Gentile believers. The acceptability of eating meat offered to idols. Whether Jesus would return in their lifetimes. Whether marriage was encouraged or discouraged. Whether women could hold leadership roles.

Salvation itself was framed in more than one way. One influential argument — later central to the Trinitarian case — held that only God can save, so the one who saves must himself be God; defenders pressed that the cross can reconcile humanity to God only if the one who died was God in the flesh, pointing to texts where Jesus forgives sins, receives worship, and is called God (Titus 2:13, John 20:28). Those who read Jesus as a human Messiah answered that God the Father saves through his exalted human Son: in Acts it is God who “raised him” and in whose name alone there is salvation (Acts 4:12), Paul calls him “the man Christ Jesus, who gave himself as a ransom” (1 Timothy 2:5), and Hebrews speaks of the single sacrifice this man offered before sitting down at God’s right hand (Hebrews 10:12). The two soteriologies were argued from the start, each appealing to scripture against the other.

These weren’t peripheral questions. They were contested from the very beginning, within the New Testament period, by people who had known the apostles personally.

What This Means for Today

When someone says “the early church believed X,” they’re almost always projecting backward from their own tradition. The early church believed many things, often simultaneously, and the version that became “orthodox” was determined — over centuries — by a combination of theological argument, political power, and historical accident.

This doesn’t mean orthodoxy is arbitrary. There are strong arguments for the positions the councils adopted, and able defenders made them. But it does mean that the relationship between “what the earliest Christians believed” and “what the councils declared orthodox” is far more complicated than a straight line. Among the positions that existed in the early church — and that were sometimes suppressed as much as refuted — was the conviction that the Father alone is God and that Jesus is his human Messiah, exalted to God’s right hand. Paul of Samosata may have held something like this in the third century (though his actual views are impossible to reconstruct with confidence from the hostile accounts of his accusers). This position persists today among biblical unitarians. Its defenders maintain that it was set aside as much through the loss of its proponents’ writings under the Theodosian state as through exegesis; its critics maintain that it was genuinely outargued. Both claims are part of the historical record’s contested aftermath.

The early church wasn’t Catholic. It wasn’t Orthodox. It wasn’t Protestant. It was something messier, more diverse, and more human than any of those categories allow.

And that’s actually encouraging. It means the truth has nothing to fear from honest inquiry — and that the search for what the earliest Christians actually believed is worth conducting without assuming we already know the answer.

Think you know which early Christians you’d have agreed with? Take the quiz and see what the councils would say.