The Dutch painter Johannes (often Jan) Vermeer (1632-1675) was born in Delft and was baptized in a Dutch Reformed church there. When he was 21, he married Catharina Bolenes, the Catholic daughter of a well-connected Delft woman, who was very much involved in a “hidden” Jesuit church (schuilkerk) next door. (It was illegal then to celebrate Mass in the Netherlands, although the Dutch were then – as now – more tolerant than some other Protestant countries. Back when that was a virtue.)
It’s assumed Vermeer embraced Catholicism before the wedding.
But he was not thereafter merely Catholic-in-marriage-only. The faith mattered greatly to him, and this can be seen clearly in one of the canvases he painted between 1670 and 1672, Allegory of the Catholic Faith  (the image below) or, as Protestant sources often refer to it, simply Allegory of Faith.
Thank goodness New York’s Metropolitan Museum, which owns the painting and features it in a new show, “In Praise of Painting ” (on display until October 4, 2020), has the integrity to call it by the name the artist intended.
That exhibit’s most prominent painting is probably Rembrandt’s Aristotle with a Bust of Homer , prominent in part because of its size – 56-1/2 x 53-3/4 inches – whereas Vermeer’s work, rather like Leonardo’s, is usually smaller, although at 45 x 35 Allegory is actually one of Vermeer’s larger paintings.
The largest also has a religious theme, Christ in the House of Martha and Mary  (63 x 56 and painted in 1655 – not at the Met). Only thirty-four paintings of Vermeer are known to exist (several others may be by him but are disputed), whereas more than 600 Rembrandts have survived. Even accounting for the fact that Rembrandt lived twenty years longer, Vermeer’s output was modest.
Much of Vermeer’s work celebrates domesticity – the people and places in Delft where he spent most of his life: a prostitute, a milkmaid, music lessons, men and women at work in the home, and several exterior scenes of Delft. My favorite of all Vermeer’s pictures is The Little Street; to my mind, an almost perfect painting.
Vermeer is perhaps best known for his depiction of light and for his use of vibrant colors: ultramarine, from the Latin for “beyond the sea,” the most intense of blues; giallolino, obviously an Italian word for what is now known as “lead-tin yellow” or yellow ochre; and the deep red cinnabar, more commonly known as vermillion.
The at-home settings depicted in most of his paintings, including Allegory, were one or the other of two rooms in his mother-in-law’s house where Jan and Catharina lived. The light, which Vermeer prized and painted with such genius, was best in those rooms. Even in his religious paintings, one finds the trappings of 17th-century Dutch life.
Most scholars believe the woman in Allegory of the Catholic Faith is the repentant Mary Magdalene, symbol of faith in Christ and of the Catholic Church. Her foot is on a globe that she seems poised to push away: she is leaving worldly life to follow Jesus. This argument is supported by echoes in the picture of paintings Vermeer (an avid collector of others’ work) would have known well, in particular, Mary Magdalen Turning from the World to Christ by Jan van Bijlert.
My own impression upon first seeing Allegory was that Vermeer was echoing paintings that depict the Blessed Virgin as she is described in the Book of Genesis, although, I thought, Vermeer’s Virgin is presented very differently. I was thinking especially of Tiepolo’s The Immaculate Conception . Our Lady upon the globe, her heel crushing the snake/a dragon/Satan. In Genesis 3:15, which follows the account of the Fall, God says to the serpent: “I will put enmity between you and the woman, and between your offspring and hers; they will strike at your head, while you strike at their heel.” In Vermeer’s painting, the serpent is crushed by a slab of stone.
Of course, when I got home from the Met and looked up the Tiepolo, I had to palm-smack my forehead: Tiepolo lived a century later.
The slab of stone crushing Satan is the “cornerstone” of Psalm 118, the one “the builders rejected [and] has become the cornerstone.” And the apple on the floor near Magdalene’s left foot is, obviously, the very one from Eden. The composition of Allegory, although more complex, is similar to Vermeer’s Woman Holding a Balance , a better and purer picture (his way with light more fully on display), in which a (possibly pregnant) woman by a window, her jewels arrayed before her, takes the measure of her life. Behind her is a painting of the Last Judgement, artist unknown.
The painting on the wall in the background of Allegory is Vermeer’s recreation, albeit edited, of Jacob Jordaens’ Crucifixion, a painting his mother-in-law, Maria Thins, likely owned. To Magdalene’s left is a home altar with what’s likely a missal and, of course, a crucifix and a chalice. The sphere hanging from the ceiling may simply represent reflection, as in contemplation, which is certainly what Mary M.’s rapt expression seems to indicate . . . or it may simply be a way for the artist to demonstrate his technical skill.
That leaves the leather screen to our right and the tapestry to the left. The tapestry appears in other Vermeer works (and in this case offers more proof that the artist used the camera obscura  technique), but it and the screen suggest devices easily deployed to quickly hide the Thins’-Vermeers’ own, small schuilkerk. Given Vermeer’s prominence in Delft and a century of cooling Calvinist tempers, it’s unlikely the great painter himself faced any danger.
But others did, Jan Vermeer knew it, and so he painted it.