The painter Joe Diggs has had ancestors living on Cape Cod since the 1800s. His step-great-grandfather, Gideon Gomes, was a Cape Verdean free man of color who bought the large property in Osterville that Diggs still calls home. “They started their homestead right here,” he says, pointing to the floor beneath his feet.

Diggs’s paintings will be displayed at the Berta Walker Gallery in Provincetown from Sept. 8 to Oct. 1 in a show titled “United We Stand,” which also includes the work of abstract painter Erna Partoll. Diggs has been showing at the gallery for “six to eight years,” he says, adding, “Somewhere in there. I don’t know. I don’t have a good grasp on time. Some days go on forever, and then a year goes by in an hour.”

Time is at the center of Diggs’s paintings, which refuses to sit neatly in one moment, place, or mood. His work is about how history — both his family’s and all Black Americans’ — permeates the present. His paintings go back and forth between a history of violence and loss and the ever-present possibility of spiritual transformation through art itself. He says that this fluidity is an “exciting language that I’m coming up with on my own. It’s just a pure language — a Joe language.”

Diggs’s journey into art began after a loss. “I had an older brother who was an artist,” says Diggs. “I always wanted to be better than him at anything he could do. He passed away when he was 19 and I was 16.” Diggs says he turned to painting to find strength in what his brother loved to do. It became a lifelong passion.

Diggs’s studio, on the second floor of his home, is overflowing with inspiration. Canvases of every size are piled on tables and on the floor and hang on every inch of wall space. Every surface holds the potential to be transformed into art.

Diggs finds that potential in discarded Chinese food containers, Olive Garden cardboard takeout boxes, Stop & Shop bags, Heineken six-pack holders, and whatever else he can find. He transforms them into paintings.

“Why are we throwing stuff away?” he asks, showing hundreds of small double-sided paintings he has created. The pieces include recurring patterns of swirling shapes, swaths of thickly painted color, and even the scores of games of Rummy 500 that he and his friend write directly onto the paintings as they play. “I just write it right there,” he says. “There’s no border between this and that.” He points to the painting and then gestures to the world around him.

The paintings, Diggs says, build on each other: “These patterns lent themselves to these patterns, which turned into almost graffiti, which itself turns into something new.” The pieces in his collection are in conversation with each other, formulating a new language that supersedes one simple meaning. Diggs speaks of the works as if they have a mind of their own. “The paintings are doing their own thing,” he says. “If I was to repeat the same themes over and over, they don’t go anywhere. But all this stuff is growing — going places.”

In addition to the smaller works, Diggs has multiple series of larger paintings that capture the stories of his family and the Black American experience. He is named after his step-grandfather, Joe Gomes, who owned a bar in Osterville called Joe’s Twin Villa. Diggs says that Joe’s was one of the first places on Cape Cod where a person of color owned a liquor license. It was a major community gathering space in Osterville. Diggs himself ran the bar for eight years.

“My grandfather always told me, ‘This is for you kids when you grow older.’ ”  Diggs says the bar represented “financial and personal freedom” and that it was “inclusive for everyone. It was the only place where you could really go and dance and party and feel comfortable.” He says the bar closed in 2008, and his brother sold the building, which is set to be demolished in the coming weeks.

Diggs says his pride in the place and his grief over its loss is “pretty much the paradigm” of his work. One painting, titled Good Bones, seems to depict the bar’s façade, but a closer look reveals the faded carcass of a whale overlaid on the image. Diggs says that, like whaling, Joe’s Twin Villa has an important historical legacy. In another piece, titled Joe’s at Sea, the bar faintly disappears on a stretch of blue water, emerging from or being swallowed by the roaring waves. In both these works, the natural world and this site of joy and loss fade into and out of each other.

Another staple in much of Diggs’s work are loops or clumped-together circles, which he says began to emerge after the 1998 murder of James Byrd Jr. in Jasper, Texas. Byrd was dragged to death behind a pickup truck by white supremacists. Diggs says that, because body parts were scattered on the road, “instead of chalk lining his whole body, [the police] had to chalk line little pieces.” Looking at the pictures “through blurry, crying eyes,” Diggs says, he could “actually see his body kind of come together a little bit and hover above the ground.” After that vision, the loops began, and they continue to appear in his work. He says they represent barriers.

“As an African American man, I just always feel barriers,” he says. “Once you climb over one, there’s another one.”

But he says the loops also evoke a “certain amount of rhythm and beauty,” a portal into something new. The loops can be seen in his more abstract work, such as an untitled piece portraying white circles descending on a multicolored lined background, as well as more representative pieces, such as the painting Independence Day, which depicts Diggs, his friend, and his friend’s grandson on Martha’s Vineyard, rubbing clay on their bodies.

The loops are simultaneously holes into nothingness and passages to redemption. They are a fitting metaphor for all of Diggs’s work, which can’t be defined as one thing — past, present, and future are interwoven with loss, rebirth, and the artist’s endless drive to create. The loops have energy; they speak to each other as they multiply and move across dozens of canvases. But where are they going? How do you describe something that is both approaching and retreating? It will take a new language, one that only Diggs can teach us.

United We Stand

The event: An exhibition of works by Joe Diggs, with Erna Partoll
The time: Sept. 8 through Oct. 1
The place: Berta Walker Gallery, 208 Bradford St., Provincetown
The cost: Free