The doctrine of the Trinity, though central to the teachings of the modern Christian churches, has no authentic basis in scripture. It is a deduction, rather than a quotation, and was formulated to resolve the conflict between the rigid monotheism of Judaism and the implied divinity of Jesus.

The one apparent reference to the Trinity, in 1 John 5:7, is a late interpolation or forgery. It appears in Latin documents (post-dating St Jerome’s Vulgate translation) but not in any of the authentic early Greek sources.

The essence of the Trinity doctrine is that the Father, the Son, and the Holy Spirit are a single entity. In the documents of the New Testament, the there are many references to the three divine beings, but they are separate entities.

The prevailing theory about the nature of Jesus evolved progressively down the decades and centuries. In Paul’s letter to the Romans, the introduction has Jesus assuming divine status at his resurrection [Romans 1:4]. In Mark, the adoption comes at baptism. In Matthew and Luke, Jesus was divine at conception. In John, Jesus is the Logos, the logic of the universe, existing before all creation [the Logos is rendered in English as “Word,” an example of linguistic vandalism which remains unparalleled in Biblical scholarship, and traces back to the difficulty Jerome had in rendering the Greek concept of the Logos into the constrained vocabulary of Latin].

In the era of the Church Fathers, the evolving Christology tried (and rejected) many interpretations. Modalism, for example, was the idea that Jesus was man and Jesus was God, but in different modes: just as a woman can be both a mother and a daughter. The Trinity evolved from the formulation that Jesus and God the Father were of one substance [Greek: homoousios].

Tertullian of Carthage, influential in the early 3rd century and a prolific author of Latin writing on Christian theology, was probably the first to formulate something close to the definitive conception of the Trinity.