One of my high school jobs was stocking shelves and tending the register at a Christian bookstore in upstate New York. “Bookstore” is a bit of a misnomer. While we did sell books — Bibles, relationship manuals about love languages, “Left Behind” novels — most of the store’s floor space was devoted to things that were not books at all, including Christian music CDs and cassette tapes plus “gift” items, usually displayed in themed zones: baptisms, amusements and brands like Willow Tree, Precious Moments and Veggie Tales.

When I was there in 2001, our biggest sellers came from one section in the store that was set up to resemble a small living room, with a couch and a rug and a wall hanging. This was the Thomas Kinkade section, named for the artist who created the images of colorful homes nestled into sweet landscapes that were then painted and embroidered and printed onto anything a typical Christian bookstore patron might desire. You could buy Thomas Kinkade collectible plates, Thomas Kinkade throw blankets, Thomas Kinkade lamps, Thomas Kinkade crosses, Thomas Kinkade mass-produced cross-stitched Bible covers. With the flick of a button, Thomas Kinkade framed prints would convert images of glowing windows to actual glowing windows via little embedded lights. You could deck your whole life out in Thomas Kinkade.

Kinkade, who turned out these original images and called himself the “Painter of Light,” is the subject of the new documentary “Art for Everybody,” directed by Miranda Yousef. Kinkade is sort of the Kenny G of American art, ubiquitous and beloved and very easy to deride. The documentary brings in a variety of art critics, journalists and historians to do just that, with reactions ranging from sniffs to an earnest consternation over what Kinkade’s anodyne, even retrograde images signify about their buyers. New Yorker writer Susan Orlean, who profiled Kinkade in 2001, provides some background from a decidedly outsider perspective: She hadn’t heard of Kinkade in his ‘80s and ‘90s heyday, and found him to be as much of an oddity as a cultural phenomenon.

But I suspect that Orlean is an outlier, and not just because, according to the documentary, at one point 1 in every 20 American households purchased “a Kinkade” — meaning a licensed print — to put on the wall, and possibly many more. For those who grew up in and around Christian culture in the United States, especially the evangelical flavor, he was ubiquitous from the 1980s onward, present in church lobbies and grandma’s living room. As art critic Christopher Knight notes in the film, Kinkade “fed on the disdain” of critics and the establishment, positioning himself as diametrically opposed to an art world seen as degenerate and anti-family during the 1980s and ‘90s culture wars. Kinkade served up a vision of a perfect, beautiful world, with himself as a defender of “family and God and country and beauty,” he says in archival video.

All of this was very lucrative for Kinkade, who was a marketing genius — one interviewee suggests that Andy Warhol may have been jealous — and an outspokenly religious family man. But that makes his death in 2012, at the age of 54, even more startling. After a precipitous decline owing to mounting alcoholism and including public urination, heckling and erratic behavior (plus a failed stint in rehab), Kinkade died of an alcohol and Valium overdose.

It was easy to write this off as an example of hypocrisy on his part, just another outwardly upright man who kept his real life secret until it burst out of him. But “Art for Everybody” — which is well structured, meticulously researched and revealing, even for a Kinkade-jaded viewer like me — manages to complicate the narrative, thanks in part to sensitive interviews with family members and friends, including his wife, Nanette, and their four daughters. Kinkade, they say, was a vibrant and multifaceted man who was forced, partly by his own fame, into showing only one facet of himself in his art: the glowing, bucolic, faith-and-family side. For instance, at various points in the ‘90s, Kinkade’s images appeared on the cover of the magazine published by Focus on the Family, the conservative evangelical organization headed by influential culture warrior James Dobson. Kinkade’s branded stores were in shopping malls, and he filmed TV shows that showcased his perfect family, loving life and deep devotion to his Christian faith.

The real Kinkade was more complex. The most surprising revelation in “Art for Everybody” is the existence of what his family calls a “vault” of his work. Only about 600 of 6,000 have been “published,” as they put it, as part of the Kinkade brand, but in the vault we glimpse thousands of works that would never hang in a Christian bookstore. They show a far more fascinating artist, one who experiments with forms and styles and frequently depicts the darkness that lurked inside him. In several images, dark brooding figures rendered in charcoal seem haunted; others feature grotesque caricatures that are bleakly humorous. There’s audiotape of him, as a youthful art student, vowing to “avoid silly and sweet and charming pictures; I want to paint the truth.” Stuffing these impulses down, the film suggests, may explain why he succumbed to addiction.

There are questions raised in “Art for Everybody” that the film lets linger rather than answering directly. What sort of culture requires artists to make themselves brands in order to make a living? The blockbuster success of Kinkade’s empire among evangelical Americans is revealing — but of what, exactly? The film prefers to let the audience draw its own conclusions. But it may not be much of a leap to see the glowing windows of Kinkade’s cottages and see, as one interviewee does, the blazing flames of a house fire that may burn the whole structure down.