The full text of this address is now available in English.
Here is an excerpt from Zenit's translation:
Dear brothers and sisters, I now wish to underline two elements of Romanesque and Gothic art, which are also useful for us.
The first: the works of art born in Europe in past centuries are incomprehensible if one does not take into account the religious soul that inspired them. Marc Chagall, an artist who has always given testimony of the encounter between aesthetics and faith, wrote that "for centuries painters have dyed their brush in that colored alphabet that is the Bible." When faith, celebrated in a particular way in the liturgy, encounters art, a profound synchrony is created, because both can and want to praise God, making the Invisible visible... [NLM emphasis]
The second element: the force of the Romanesque style and the splendor of the Gothic cathedrals remind us that the via pilchritudinis, the way of beauty, is a privileged and fascinating way to approach the Mystery of God. What is beauty, which writers, poets, musicians, and artists contemplate and translate into their language, if not the reflection of the splendor of the Eternal Word made flesh? ...