What you're looking at here is the high altar at Karlskirche (St. Charles Church) in Vienna. We visited this cathedral on June 6, 2016. This church we erected in honor of St. Charles Borromeo (1538–1584), patron saint of plague sufferers. In 1713, a plague epidemic ravaged Vienna. It lasted until 1716, and more than 8000 people died. Borromeo, archbishop of Milan, came to Vienna to care for the suffering. Many people were restored to health under his care. [NOTE: Borromeo was also quite an academic and, not surprisingly given that he was an archbishop, theologian who was also heavily involved in the so-called counter-reformation.]
This cathedral is obviously late baroque, even rococo, as the high altar gives away in its attempt to capture light and movement in an almost gaudy manner. The scene depicted in the altar (remember, altars were not just about sacrifice and offerings and religious services; they were also meant to tell a story [esp. in Baroque period when style was used to communicate who was large and in charge]) is the apotheosis of Charles Borromeo (i.e., his ascension into and achievement of sainthood). He is the person in the middle presumably riding the clouds to heaven. Above him is a triangle with the Hebrew characters of YHWH in the center. Obviously this represents God in three persons (hence the triangle). Emanating from the triangle are beams of light (all in gold, by the way—rococo style); these are almost like tractor beams, if I may, drawing Borromeo up to heaven into the presence of God. Seated just below The Deity, to the lower left and right as you look at the altar, are sculpted statues of the Church Fathers Ambrose, Gregory, Jerome, and Augustine. These represent the Magisterium of the (Roman Catholic) Church who are not only onlookers of the apotheosis of Charles, but also serve as reminders to the people in the pews that, in Roman Catholic tradition, only the Church has the authority to interpret and explain what is in the gospels—it's difficult to see, but the four evangelists (Matthew, Mark, Luke, and John) are represented in lower relief than these Church Fathers, which adds to this statement.
On that last point, let me share one last photo and comment about Karlskirche—and this is a point that I asked our students to pay attention to—about how Baroque art and style was used to communicate not only a story but also to make a statement about who was really "in charge." If the Magisterium of the (Roman Catholic) Church was the only body authorized to interpret and communicate the scriptures, then it's no surprise to find waaaay up in the dome painted on the ceiling a picture of Martin Luther in torment and an angel lighting his translation of the Bible on fire!