The Heresy Nobody Told Me I Believed

I grew up in a nominally Christian household. Church visits were limited to weddings, christenings, and funerals. In school, we attended religious education classes and said the Lord’s Prayer in assembly. But I came away from it all with no real understanding of who the Christian God is. I had heard the words “Father, Son, and Holy Spirit,” but I always assumed Jesus was God’s son in a literal sense. Subordinate to the Father. A powerful figure, certainly, but not God himself.

I have since discovered that this view was close to a heresy called Arianism, named after a fourth-century priest called Arius, who taught that Jesus was not eternal. “There was a time when the Son was not,” Arius argued. To many people, this made perfect sense. It preserved a cleaner form of monotheism. It felt more intuitive to see Jesus as God’s highest creation rather than somehow being God himself.

The debate came to a head at the First Council of Nicaea in 325 AD. The Church had to decide: was Jesus fully God, sharing the same divine essence as the Father, or was he the greatest created being? The Council ruled that Jesus was of the same substance as the Father. God had not sent a representative. He had come himself.

I never much considered what followed from this. The question of who exactly Jesus was had not seemed to me to have practical consequences. I was wrong. The logic of the Trinity, once followed through, leads somewhere remarkable.

The word “person” in the phrase “three persons, one God” is misleading to a modern reader. We think of persons as separate individuals with separate minds. If that were what the Trinity meant, it would simply be three gods. That is not the claim.

The three persons of the Trinity are distinct, but they share one divine nature, one will and one essence. The distinctions between them are relational. The Father is defined by his relation to the Son. The Son is defined by his relation to the Father. The Spirit proceeds from both. They are not separate beings who cooperate. They are one God whose inner life is inherently relational.

Therefore, a relationship is not a contingent act of God’s will. It flows necessarily from his nature, an eternal expression of who he is.

Being made “in the image of God” then carries a specific implication. Humans were created by a relational God and designed for relationship in a way that echoes his own inner life.

The Christian claim goes further. The relationship humans were made for reaches into participation in the relational life of God himself. The theological term for this is theosis. Humans were intended to be drawn into the life of the Trinity, not as equals, but as genuine participants. The purpose of human existence, in this framework, is not merely to obey God or to be morally good. It is to share in the kind of living, reciprocal relationship with God that already exists within the Trinity.

In John 15, Christ describes himself as the vine and his followers as the branches. This image implies a relationship that goes far beyond one of obedience and moral instruction. He is describing an organic, living connection, with the life that flows through the vine being that of God himself.

If humans were designed for this kind of participation in divine life, then the rupture described in the Christian account of the Fall is not primarily a moral infraction. A being designed for relationship has been severed from the source of its own life. The stakes are existential.

Restoration must address the rupture in full. Sin carries both a moral dimension — the guilt and disorder that bars re-entry — and a relational one — the broken connection itself. Forgiveness removes the moral obstacle. Restored connection heals the severance. Only God can accomplish both. He forgives sin and enters the human condition to mend what was broken.

A representative cannot accomplish this. A drowning man cannot be saved by instructions shouted from the shore. Someone has to enter the water.

The Incarnation, on this reading, is God entering the human condition from within. Not sending the most qualified representative possible, but coming himself to forgive the sin that caused the rupture and restore the connection the rupture destroyed. Christ assumes human nature, takes it into himself, and, in doing so, addresses both at once.

This is why the Nicene Creed matters when it states the Son is “begotten, not made.” God exists outside time. The relationship between Father, Son and Spirit is not a sequence of events but an eternal state. There was never a time when the Son was not. Hence, the Arian view, which places the Son’s origin inside time, undercuts the very logic of this salvation.

The resurrection demonstrates that human nature can participate in divine life. The ascension establishes that bridge permanently, as Christ takes glorified human nature into the eternal life of the Trinity. The sending of the Holy Spirit follows naturally. Divine life flows freely through that open connection, available to all.

This doctrinal choice shapes two distinct experiences of faith, and the difference is practical.

Consider the Arian perspective first, the one many hold without realising it. If Jesus is the greatest created being, his sacrifice on the cross stands as a powerful gesture from God. It demonstrates forgiveness and satisfies justice through a sufficient act of atonement. Jesus provides the supreme moral example by which we should live. All of this is coherent and compelling on its own terms. Yet God remains on one side and humanity on the other. The cross settles a debt but does not open an ongoing connection. Jesus shows you how to live, but he does not draw us into a life already lived within God. In this framework, God exists as an authoritative Father. The fitting response is obedience. Faith becomes gratitude, moral effort and imitation. You study the example, try harder, and hope it proves enough. The Kingdom of God remains external and future, a prize held at a distance, awarded to those who perform well.

The Trinitarian account offers something structurally different. The sacrifice is God himself entering brokenness. The resurrection shows human nature taken up into divine life. The Holy Spirit is God present from within, permanently. The relationship on offer is participation in the same mutual presence that defines the Trinity’s inner life. The Kingdom of God is not deferred. It is the present reality of life lived inside that connection, available here and now.

The practical difference is this. One path calls us to live up to an example through effort. The other sustains us through a living connection. Obedience remains important, but it flows from a relationship rather than replacing it.

It is striking that my own childhood misunderstanding mirrored the very error the doctrine corrected. I saw God as distant and hierarchical. I understood faith as performance. Without knowing it, I had adopted the Arian framework, and it produced exactly that kind of distant faith. A God who sends a representative stays at a distance.

The Trinitarian claim changes everything. God has not stayed distant. He has entered. He remains. The vine is alive, and the life flowing through it is his own.