Most Christians believe in the Trinity because it became the official doctrine of institutional Christianity—not because the Bible clearly defines God as three persons.

The doctrine developed gradually as church leaders debated the relationship between God and Jesus. At the Council of Nicaea in AD 325, the Son was declared to be “of the same substance” as the Father. At Constantinople in AD 381, the doctrine was expanded and established more firmly as official orthodoxy. Imperial support then gave Trinitarian Christianity the power to exclude rival interpretations.

For centuries, Christians who rejected the Trinity could be removed from office, exiled, silenced or even executed. Consequently, Trinitarianism became embedded in creeds, seminaries, liturgies and denominational statements. Most believers today inherit the doctrine before personally examining whether Jesus and his apostles taught it.

This does not mean most Trinitarian Christians today are doing the same or insincere. But the point is whether this teaching is biblical. Jesus himself quoted the Shema from Deut 6:4 which is inherently unitary not trinitarian monotheistic creed. And he prayed to his God and Father:

“This is the life of the age to come: that they may know You, the only true God, and Jesus Messiah whom You commissioned.” John 17:3

Paul did not modify, split or replace the Shema when he says:

“For us there is one God, the Father…and one lord Jesus Messiah.” 1 Corinthians 8:6

This same belief is reflected by all official ecumenical conciliar creeds that begin:

“We believe in one God, the Father, the Almighty, maker of heaven and earth, of all that is, seen and unseen.”

The popularity of a doctrine demonstrates its historical influence—not necessarily its biblical truth. Christians should respectfully test every inherited belief by the words of Jesus and the apostles.

“For us there is one God, the Father.”