It is something seen and known in lesser poems.
It is the huge, high harmony that sounds
A little and a little, suddenly
By means of a separate sense. It is and it
Is not and, therefore, is. In the instant of speech,
The breadth of an accelerando moves,
Captives the being, widens--and was there.
One poem proves another and the whole,
For the clairvoyant men that need no proof:
The lover, the believer and the poet.
Their words are chosen out of their desire,
The joy of language, when it is themselves.
With these they celebrate the central poem,
The fulfillment of fulfillments, in opulent,
Last terms, the largest, bulging still with more,
The central poem is the poem of the whole,
The poem of the composition of the whole,
The composition of blue sea and of green,
Of blue light and of green, as lesser poems,
And the miraculous multiplex of lesser poems are brought then:
Not merely into a whole, but a poem of
The whole, the essential that is compact of its parts,
The roundness that pulls tight the final ring
And that which in an altitude would soar,
A vis, a principle or, it may be,
The meditation of a principle,
Or else an inherent order
active to be
Itself, a nature to its natives all
Beneficence, a repose, utmost repose,
The muscles of a magnet aptly felt,
A giant, on the horizon, glistening,
And in bright excellence adorned, crested
With every prodigal, familiar fire,
And unfamiliar escapades: whirroos
And scintillant sizzlings such as children like,
Vested in the serious folds of majesty,
Moving around and behind, a following,
A source of trumpeting seraphs in the eye,
A source of pleasant outbursts on the ear.
[Wallace Stevens, excerpted from "A Primitive Like an Orb."]
Wallace Stevens was not a believer (at least not in the sense of Dickinson, Hopkins, Eliot, or Auden), but he's close in his intuition here, and in his expression of it, to the basic intuition of the Logos, (aka the Word) affirmed by the Greeks of old and the Romans. Christians identify the Logos with the Christ. Christians think of the Logos as both the ground of being, in which "all things were made, and not one thing was made without him." The Logos is the foundational matrix in which everything that existis exists.
So whether one identifies the Logos/Word/Poem with Christ or not--Stevens would not--this fundamental intuition that Stevens is trying to articulate marks the difference between people who "get it" and those who don't, if by getting it we mean "knowing" that our existence in this world given to us through our senses is embedded in something larger with unfathomable depths of meaning, depths the poet makes feeble attempts to fathom. This isn't something you believe; it's something you know in the way that Stevens knows it. And so long as it is recognized, intuited, it's the common ground, the meeting place where we can gather to be refreshed and where there exists already the foundation upon which to build something new.
Because I believe that this 'Poem' in which we all subsist is the soil from which all good things grow. I believe in renaissances, springtimes of the spirit, moments in history when the ground softens and brings forth new life. These moments occur when this intuition about the foundation of things becomes more broadly recognized and experienced, and is expressed in a superabundance of ways by a culture's great artists and philosophers. This springtime, this new thing, is a very old thing, but it's the source of everything new, a new that cannot happen unless we humans find an unalienated way to think and speak. And the measure of this unalienation is the measure of our communion with the Logos. It doesn't matter whether we identify if with the Christ; it matters only that we recognize it and seek to live in a deeper communion with it.
This is not easy, but we overcome our alienation by sinking into the thisness of the real, by sinking into the foundations, which is the Logos, which is the heart of things. We don't want to go there. We'd rather live in our dreams. But it's the Dream in all its manifestations that is the cause of our alienation. What waking up means is different for each of us. But the only moral question that really matters is to what degree are we awake, and what are the temptations in our life that draw us back into sleep. It's so easy to fall back to sleep.
We humans can bear only so much reality, and I don't think we have to deal with the enormity of it. But we know where deep communin beckons to us, and we know when we hearken to it or turn away. And we are inclined turn away because where it beckons too often we see Christ crucified, and we'd rather not deal with that. But that's a subject for another day.