How we cite our quotes:
[St. Peter to Dante]: "What is the origin of the dear gem
that comes to you, the gem on which all virtues
are founded?" I: "The Holy Ghost's abundant
rain poured upon the parchments old and new;
that the syllogism that has proved
with such persuasiveness that faith has truth –
when set beside that argument, all other
demonstrations seem to me obtuse." (Par. XXIV, 89-96)
Dante cites the Holy Ghost, the third member of the Holy Trinity, as the source for all faith. His "persuasiveness that faith has truth" is supported by Jesus in John 14:15-18, where He calls the Holy Ghost the "Spirit of Truth." This links back to why faith is seen as "evidence" for the unseen truths of Paradise and its blessedness.
I answer: I believe in one God – sole,
eternal – He who, motionless, moves all
the heavens with His love and love for Him;
for this belief I have not only proofs
both physical and metaphysical;
I also have the truth that here rains down
through Moses and the Prophets and the Psalms
and through the Gospels and through you who wrote
words given to you by the Holy Ghost.
And I believe in three Eternal Persons,
and these I do believe to be one essence,
so single and threefold as to allow
both is and are. Of this profound condition
of God that I have touched on, Gospel teaching
has often asset the imprint on my mind.
This is the origin, this is the spark
that then extends into a vivid flame
and, like a star in heaven, glows in me." (Par. XXIV, 130-147)
Dante recites his creed, a religious confession of faith beginning with his belief in "one God." He cites Scripture, both books in the Old Testament ("Moses and the Prophets" and the "Psalms") as well as those in the New Testament ("the Gospels" and the writings of the Apostles) as proof of God's existence. He then goes on to map the triune form of God in the Holy Trinity – in which there are Three in One and One in Three. This allows God to be called by the singular "is" or the plural "are." As a statement of truth, this creed ends in a bit of light imagery – a "spark," "vivid flame," and "star in heaven" – which enlightens Dante and "glows in [him]."
That circle – which, begotten so, appeared
in You as light reflected – when my eyes
had watched it with attention for some time,
within itself and colored like itself,
to me seemed painted with our effigy,
so that my sight was set on it completely.
As the geometer intently seeks
to square the circle, but he cannot reach,
through thought on thought the principle he needs,
so I searched that strange sight: I wished to see
the way in which our human effigy
suited the circle and found place in it –
and my own wings were far too weak for that. (Par. XXXIII, 127-139)
Dante's final lasting image in Paradiso is of the second circle (the Son) of the Holy Trinity. Here he witnesses the mystery of the Incarnation, that Christ had both the nature of man and God in one body, symbolized by the fact that "our effigy" (the image of man) "seemed painted" on the second circle but was "colored like itself." In other words, man's image is the same color as the rest of the circle around it, but yet Dante can see it. Seeing, however, does not necessarily mean understanding. When Dante ponders it ("I wished to see / the way in which our human effigy / suited the circle"), he cannot comprehend it ("my own wings were far too weak").