In my debate with Musharraf Hussein (listen to the audio, read some follow-up reflections here and here) he made the claim repeatedly that Trinity was a late development. He reckoned the doctrine was thrust onto the church by Constantine in the 4th century at the Council of Nicaea.

Such an assertion is not uncommon. The underlying thought is that everyone was unitarian until a few nefarious characters hijacked Christianity. Maybe the chief baddie was Paul, maybe it was Constantine, but somebody sullied the pure doctrine of Tawhid and we had to wait till the 7th century for Muhammad to put people right again.

What’s worrying is that many Christians seem to share similar thoughts about Trinitarian trajectories. Some think that the Old Testament was essentially unitarian but that there was a shift in the 1st century to trinitarianism. If such a position is assumed it becomes difficult to disagree with a Muslim who reckons we should stick to Moses and the Prophets. If unitarianism is original, why complicate matters? And if the New Testament is such a big development/departure, why aren’t there any chapters in Paul’s letters that begin, “Now, regarding the matter of the Trinity. The Spirit has revealed the doctrine in these last days and so we now declare to you what was kept hidden in ages past…” In fact why does no-one ever attempt to teach the Trinity? It’s always just assumed.

I think this tells us that we’ve been working with faulty trajectories.

The faulty Muslim trajectory says:

There’s a foundation of unitarianism and the key date for development was the 4th century. Later, in the 7th century, Islam put things right, returning to Moses’ doctrine of God.

The faulty Christian trajectory says:

There’s a foundation of unitarianism and the key date for development was the 1st century. In the 7th century, Islam failed to follow the new trajectory and remained with Moses’ understanding.

But the true Christian trajectory says:

The foundation is essentially trinitarian (or proto-trinitarian) and the key dates for development were the 2nd and 7th centuries AD when Jewish and then Muslim theologians rejected Christianity. It’s Christianity alone which has maintained Moses’ doctrine of God.

Let me unpack this third position.

Moses’ doctrine of God was of a multi-personal Being. God is one – Moses proclaims it proudly (Deuteronomy 6:4). But this one-ness is a compound unity. Throughout the Old Testament, God approaches people through his Word/ Glory / Angel, who is both from the LORD and is the LORD. (See many Old Testament passages where this truth lies right on the surface). Moses’ doctrine of God is emphatically not Muhammad’s doctrine of God. And nor is it Maimonides’ doctrine of God (Maimonides was a 12th century Jewish theologian heavily influenced by Aristotle and hugely influential on modern day Jewish theology).

The “development” is not from a unitarian Old Testament into a trinitarian New Testament. To think this way is to grant to Muslim and modern Jewish theologians that they are right about Moses but that Christians have departed from him. This is not the way the New Testament argues.

No, trinitarianism is not the development, unitarianism is. In fact, to call it a development is incorrect. Unitarianism is a devolution, a corruption. Alan Segal, a Jewish theologian, wrote The Two Powers in Heaven to show that it was commonplace in the 1st century to believe in Two Powers: the Ancient of Days together with the Son of Man; The Most High God together with His great High Priest, the Word; etc; etc. Such teaching was uncontroversial and promulgated by colossal figures like Philo of Alexandria. It was only in the second century AD that the Jewish authorities, in reaction to Christianity, began to distance themselves from this teaching. Jewish scholars like Segal acknowledge that it was precisely because “Two Powers” theology sounded so Christian that the Jews began to anathematise it.

More and more, those who rejected Christ began to harden against the doctrine of God that Christians were proclaiming (and remember, Christians were proclaiming it from the Hebrew Scriptures). More and more though the enemies of Christianity became anti-trinitarian. It got to the point where, in the 7th century, a new ‘prophet’ arose so opposed to the Trinity he came to the world with a new religious text: one shot through with quips like “Say not three” and “God does not beget, nor is he begotten.” That is the real trajectory for unitarianism – a corruption from Moses’ original doctrine of God, accelerated decisively by the coming of God’s Son in the flesh.

When it comes to grasping Moses, neither Muhammad nor Maimonides are much help. Those thinkers represent a departure from the original teaching of Scripture. The Bible’s bedrock doctrine of God is emphatically not unitarian. This means that as Christians we don’t have to choose between our Hebrew roots and trinitarian theology – they are entirely of a piece. It is modern Judaism and Islam that reckon they have to choose. And in rejecting the Trinity they have lost both Moses and his God.