From "Old Possum's Book of Practical Theology" and with apologies to T.S. Eliot and his Mystery Cat.
The Trinity's a Mystery quite: it makes us sit and pause— for it's a matter doctrinal that can defy all thought. It's the bafflement of bishops and the laity's despair: for when they seek analogies—the Trinity's not there! The Trinity, the Trinity, there's nothing like the Trinity, it's broken every human thought, it obfuscates lucidity. Its need for erudition defeats the preacher's flair, despite our best analogies—The Trinity's not there! You may try the three-leafed clover; hah! you haven't got a prayer— I tell you, not just partially: the Trinity's not there! The Trinity's a catalogue of snares to catch you out; You won't know them, you won't see see them, for at first you have no doubt. The Hypostatic Union is child's play, yet it warns of lurking traps within the complex Filioque Clause. And when of Athanasius you've had a dose or two, it dawns: you haven't mastered it; it's come to doctor you. The Trinity, the Trinity, there's nothing like the Trinity, Not even subatomic wave and particle duality. Your egg shell, yolk and albumen? So naive; so unaware. Despite your best analogies—the Trinity's not there! It's outwardly presentable, in creeds: just take a look; and its footprints are in other pages of our service book. And when the psalms are finished (if our service has psalms in it) we tack on one more verse to Father, Son and Holy Spirit. But if the preacher tries to tell you what it means... beware! The chances are, whate'er he says: the Trinity's not there! The Trinity, the Trinity, there's nothing like the Trinity; a statement of identity, three persons in propinquity. You may speak of water, steam and ice as something to compare, but that is modal heresy: the Trinity's not there! And when the Great Church Councils at Nicaea and at Tyre called Arius to give account, his feet close to the fire, the pugilist Saint Nicholas was prompted to declare: "That's Sabellian heresy! the Trinity's not there!" Of heresies both great and small, they did a mighty purge, and ratified the doctrines and the teachings of the Church. And out went patripassianism, docetism too, for we must have the Trinity whatever else we do. The Trinity, the Trinity, there's nothing like the Trinity, there's never been a match for such a co-equal divinity. It's always there to snag you; for whatever you declare, whatever likeness you might try—the Trinity's not there! And they say that all theologies however false or true (I might mention consubstantial, and co-eternal too) are nothing more than shadows of Theology Untamed: of Father, Son and Holy Ghost, from age to age the same.