“Within the depthless deep and clear existence of that abyss of light three circles shone – three in color, one in circumference: the second from the first, rainbow from rainbow; the third, an exhalation of pure fire equally breathed forth by the other two.” (Canto XXXIII)
Who dares to say what we will see when we see God “face to face.” Dante dared; should he have?
“If any one, therefore, says to us, ‘How then was the Son produced by the Father?’ we reply to him, that no man understands that production, or generation, or calling, or revelation, or by whatever name one may describe His generation, which is in fact altogether indescribable. Neither Valentinus, nor Marcion, nor Saturninus, nor Basilides, nor angels, nor archangels, nor principalities, nor powers [possess this knowledge], but the Father only who begot, and the Son who was begotten. Since therefore His generation is unspeakable, those who strive to set forth generations and productions cannot be in their right mind, inasmuch as they undertake to describe things which are indescribable.” -St. Irenaeus of Lyons
Certainly, many a Father and Doctor of the Church would qualify, by St. Irenaeus’ standards, as not in their right mind. But as Aristotle and St. Thomas say, to achieve even a little knowledge of the highest things is far better than to know almost everything about worldly things.
The extreme difficulty of finding words to describe the vision in heaven is hardly made any easier by Revelation. How will, indeed, we “see” the threeness and oneness of God? We cannot do such here, not through creation.
God is One, and He acts as one. We can know that God exists through reason alone, but this is reasoning from cause to effect, and in this case, we recognize a “necessary cause” for all that is contingent. We can only reason to the one cause, which is the one nature, the one essence that is the one God. There is no way to know (through reason) that there is a Trinity.
In heaven, of course, we will see God not through some other medium, but directly. This must be the key to seeing God, three and one. But still, to describe it in human terms must truly be impossible. Yet we should not fault Dante, but rather praise him, for saying what he can. After all, many things we try to describe here on earth fall short (I hope) of what we actually conceive. One’s love of a spouse and children, for example; I may try to express to my wife my love for her, but human language falls short.
In the prologue to Book II of St. Augustine’s de Trinitate it is written, “men seek to know God, and bend their minds according to the capacity of human weakness to the understanding of the Trinity; learning, as they must, by experience, the wearisome difficulties of the task, whether from the sight itself of the mind striving to gaze upon light unapproachable.”
But at the end of the Divine Comedy, indeed, what makes it a comedy (a story with a happy ending) is what will make all of our lives a comedy; we will see God face to face, as He is. He will call us friends.