An MRI scan gives more details about someone than a portrait, but it is the portrait that conveys personality. Dating agencies ask for photographs, not X-rays.
So it is with using diagrams and natural analogies to explain the Blessed Trinity. They are inadequate for conveying the oneness of threeness.
For instance, to compare the Father, Son and Holy Spirit to water, which can be liquid, ice and steam, would mean that the Father morphs into the Son and the Son into the Holy Spirit. As a formal heresy, this is called modalism, condemned at the Council of Constantinople in 381.
A similar mistake is to portray the Father as Creator, the Son as Redeemer, and the Holy Spirit as Sanctifier, as if they were divided in their actions. The beguiling image of the Trinity as sun, light and heat is the heresy of Arianism, depicting the Son and Holy Spirit as creatures of the Father.
The legend of Saint Patrick using a shamrock to explain the Trinity to the Druids on Tara makes the mistake of partialism, depicting the Three Persons of the Godhead as different parts of one God, as though each were one-third of the whole. God is one Being who is three Persons, and not one Being who is three parts.
The shamrock story was first mentioned more than 1,000 years after Patrick died. That great saint was imbued with Trinitarian theology and referred to the Three in One in his “Confessio,” with a mystical rapture capturing the mystical essence of God as a lover singing a song, and not as a technician performing a biopsy.
The Feast of the Most Holy Trinity follows Pentecost, because only God can explain himself: “When the Spirit of truth comes, he will guide you into all the truth” (John 16:13). Limited human intelligence complicates the simplicity of the Three in One.
In Islam, the Trinity is considered a blasphemous denial of the One God (Koran 4:171; 5:73; 5:116) and no wonder, since Mohammed thought Christians worshipped the Virgin Mary as the Third Person.
Modern heresies are even cruder: Mormonism multiplies the Trinity into polytheism, by which any man can become a god. For Jehovah’s Witnesses, like the Arians, Christ is a creature and therefore not divine.
Saint Paul travelled more than 10,000 miles, mostly on foot, and painfully so, since tradition says his legs were misshapen. He declared the Trinity, not with formulas, but often in triple cadences like a hymn.
This was the great secret that the Son of God finally made public at his Ascension (Matthew 28:19).
Had humans invented the Three in One as a concept, it would be perfectly lucid. Instead, it is not a puzzle, but it is a mystery, which is why the saints can say in awe: “I am not making this up.”
Fr. George William Rutler is a Catholic priest and the pastor of the Church of St. Michael in Manhattan. This article from his parish church bulletin is used by permission.