William Reed Huntington, in a series of lectures that were published in 1870 as The Church Idea, posited a future for Protestantism in American that was called “The Church of the Reconciliation.” His basic premise was that some 350 years after the Great Reformation and the many theological squabbles that followed that the Protestant denominations in America were so similar to one another, that it wouldn’t take much for them to reunite as a Pan Protestant American Catholicism. Rather than getting caught in the weeds of doctrine, Huntington suggests that the historic creeds are all that is needed as a shared doctrine of the Church of the Reconciliation.
“In the Church of the Reconciliation no more ought to be demanded of the laity, on the score of theology, than an affirmative answer to the question, ‘Dost thou believe all the articles of the Christian Faith as contained in the Apostles’ Creed?’ and no more ought to be demanded of the clergy than assent to the same articles of faith as they are more exactly stated and more fully expanded in the Nicene Creed.”
The fullness of our understanding of the Trinity, for Huntington, was found in the Nicene Creed, for clergy, and the Apostles’ Creed, for laity. In the almost 150 since, some have suggested that even that is too high a doctrinal bar. I’m not willing to lower the bar beyond the historic creeds, but I do understand the feeling of Dorothy Sayers, who sixty years after The Church Idea articulated the feeling most of the clergy and laity I know have about the doctrine of the Trinity
Q.: What is the doctrine of the Trinity?
A.: “The Father incomprehensible, the Son incomprehensible, and the whole thing incomprehensible.” Something put in by theologians to make it more difficult—nothing to do with daily life or ethics.
So what is the basic requirement of belief in the Trinity if the doctrine can’t be articulated by metaphor, can’t be understood by mortals, and can’t possibly sum up the fullness of the Godhead? I think the Collect for Trinity Sunday tells us all we need to know:
“Almighty and everlasting God, you have given to us your servants grace, by the confession of a true faith, to acknowledge the glory of the eternal Trinity, and in the power of your divine Majesty to worship the Unity…”
Acknowledge the glory and worship the Unity. There is nothing in there about comprehending the mystery. Noting about properly articulating the difference between homoousios and homoiousios. Orthodoxy flows, it would seem, from orthopraxis. In acknowledging the beauty, splendor, and magnificence of the fullness of the Godhead through worship, we accomplish all that is properly required for Trinitarian belief. The rest, as Dorothy Sayers might say, is for theologians to mess around with.
So here’s your task, dear reader, on Trinity Sunday. Show up at church, worship the fullness of God’s majesty in the midst of the mystery and God might just answer our prayer to one day see God in his full and eternal glory.
 The Church Idea, 171.