God lives and reigns eternally, a Trinity in unity. As Pope John Paul II put it: “God in His deepest mystery is not a solitude, but a family, since He has in Himself fatherhood, sonship, and the essence of the family, which is love.” God is love, an eternal communion of life-giving love: Father, Son, and Holy Spirit.

The Blessed Trinity is eternal, changeless, undivided, and without beginning or end. The Greek word trias, however, had a beginning in the literary record. It first appears with Theophilus of Antioch about A.D. 180. Tertullian debuts the Latin word Trinitas just a few years later.

The Fathers preached the doctrine, argued for the doctrine — and some died for the doctrine in its purity. Many of the intra-church disputes of the patristic era were bound up with this central dogma of Christian faith.

The Fathers wanted to know God as He is, in His deepest mystery. The mystery could not (and cannot) be dissected and stuffed into a rationalist box, not even by a man as brilliant as Arius. God cannot be comprehended, but He wills to be known. And for the grace of that knowledge the Fathers prayed…

Lead me closer to the tree
Of all life’s eternity;
Which, as I have pondered, is
The knowledge of God’s greatnesses:
Light of One, and shine of Three,
Unto whom all things that be
Flow and tend!

That’s from “Soul and Body,” a long poem by St. Gregory Nazianzen (translated here by Elizabeth Barrett Browning).

And these are the concluding words to St. Hilary of Poitiers’ treatise “On the Trinity.” I broke up the lines, because they read like poetry to me.

I beg You, Father,
keep this my pious faith undefiled,
and even till my spirit departs,
grant that this may be
the utterance of my convictions:
so that I may ever hold fast
that which I professed
in the creed of my regeneration,
when I was baptized
in the Father, and the Son, and the Holy Spirit.
Let me, in short, adore You our Father,
and Your Son together with You.
Let me win the favor of Your Holy Spirit,
Who is from You, through Your Only-begotten.
For I have a convincing Witness to my faith, Who says,
“Father, all Mine are Yours, and Yours are Mine,”
my Lord Jesus Christ, Living in You, and from You, and with You,
forever God:
Who is blessed forever and ever. Amen.

The Trinity is eternal. The revelation of the Trinity came with the incarnation of God the Son. The theological term is just a little late on the scene. The feast day is wonderful, but it came in still later than the period we’re pondering in this blog. Here’s the Catholic Encyclopedia):

In the early Church no special Office or day was assigned for the Holy Trinity. When the Arian heresy was spreading the Fathers prepared an Office with canticles, responses, a Preface, and hymns, to be recited on Sundays. In the Sacramentary of St. Gregory the Great there are prayers and the Preface of the Trinity.

We’d be remiss not to mention the great legend of St. Augustine, walking the beach in North Africa, pondering the Trinity. Along the way, he saw a child hauling buckets of ocean water and pouring them into a hole in the sand. Augustine said to him “You can never succeed in emptying the ocean into that little hole.” The child replied: “I’ll empty the ocean into that little hole before you understand the mystery of the Trinity with your little mind.”

What we cannot comprehend, we can love, and by grace we may come to know, ever more deeply, as did our Fathers before us.