For many thoughtful people hovering on the edges of faith, the Trinity is a stumbling-block. For both Jews and Muslims, it comes perilously close to polytheism. For the philosophic psychologist Jung it was a sign of incompleteness, in the Catholic Church suitably completed by the Blessed Virgin Mary. Even for many of the faithful, it is a puzzlement elevated to a mystery. So it is worth thinking about.
St Athanasius, that uncompromising Church Father whose Creed is printed in the Book of Common Prayer as the Quicunque Vult, wrote a magnificent letter in which he explains the Trinity. Here are two excerpts:
“We acknowledge the Trinity, holy and perfect, to consist of the Father, the Son and the Holy Spirit. In this Trinity there is no intrusion of any alien element or of anything from outside, nor is the Trinity a blend of creative and created being. It is a wholly creative and energising reality, self-consistent and undivided in its active power, for the Father makes all things through the Word [the Son] and in the Holy Spirit, and in this way the unity of the holy Trinity is preserved. Accordingly, in the Church, one God is preached, one God who is above all things and through all things and in all things. God is above all things as Father, for he is principle and source; he is through all things through the Word; and he is in all things in the Holy Spirit.”
“Even the gifts that the Spirit dispenses to individuals are given by the Father through the Word. For all that belongs to the Father belongs also to the Son, and so the graces given by the Son in the Spirit are true gifts of the Father. Similarly, when the Spirit dwells in us, the Word who bestows the Spirit is in us too, and the Father is present in the Word. This is the meaning of the text: My Father and I will come to him and make our home with him. For where the light is, there also is the radiance; and where the radiance is, there too are its power and its resplendent grace.” (Letter to Serapion)
I find this admirably clear and wholly convincing. What is still difficult, once one has absorbed it, is the complementary understanding of the Unity. Once one has grasped the identity and the relation of the three Persons of the Trinity, one wrestles with the fact that “they are” One God. In Athanasius’ explanation of the Unity, God as above all things as their principle and source and Creator is understandable. God as in all things as the indwelling Holy Spirit also makes sense. Where it becomes harder is when A. sees God being through all things as the Word, or the Son. What, here, does “through” mean? I think that it becomes easier if we change the verb. God does all things as the Source and Creator of them; He does them through (dia, per, via) the Word; and He does them in the Spirit. This leads us back to the Gospel of St John. “In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by him; and without him was not anything made that was made.” And, as Athanasius reminds us elsewhere, Jesus also says, “Who has seen me has seen the Father.”
In the full sense all this is of course well beyond our complete understanding. We see very much as in a glass, darkly. Our window is grubby, and our binoculars ill-focused. But we can get something of a sense of this vast core of our faith. Pater (non) e(s)t Filius (non) e(s)t Spiritus Sanctus. Its dazzling strangeness reminds me of what Tertullian (or someone close to him) wrote of the death and resurrection of the Son of God: et mortuus est dei filius: [prorsus] credibile est, quia ineptum est. et sepultus resurrexit: certum est, quia impossibile. “The Son of God died: this is utterly believable because it is improper. And having been buried, He rose again: this must be true (is certain), because it is impossible.”