M ary Flannery O’Connor, one of the great fiction writers of the 20th century, was familiar with life’s dark side. Her father died of lupus when she was 15 years old. And in 1952, at age 25, she was given the same diagnosis, which she endured for more than a decade until her death at age 39.

Yet it was not so much her suffering that inspired her strange and sordid stories. But rather it was her interest, informed by her Catholic faith, in “the action of grace in territory held largely by the devil.”

She explained: “In my stories a reader will find that the devil accomplishes a good deal of the groundwork that seems to be necessary before grace is effective.” She knew that what she wrote would be “read by an audience that puts little stock either in grace or the devil.” Still, she knew what she was doing. In her prayer journal, she asked God: “Please help me to get down under things and find where You are.”

Ethan Hawke’s new biopic about the author, Wildcat, which he worked on with his daughter, Maya, in the role of O’Connor, takes the author’s religious views as a theme but fails to integrate it into a coherent narrative. The movie is a series of scenes from O’Connor’s early career in her twenties, interrupted by stories, seemingly at random, as inspiration strikes.

Hawke portrays O’Connor’s Catholicism through rosary beads, the sacraments, her fiery remark to another writer (in real life, Mary McCarthy) about the real presence of Christ in the Eucharist: “If it’s a symbol, then to hell with it.”

But as for grace — the excerpted stories give us only a hint, mostly inaccessible to those not already familiar with O’Connor’s work. In “The Life You Save May Be Your Own,” Tom Shiftlet (Steve Zahn) works as a handyman and marries his employer’s disabled daughter (Maya Hawke). On their honeymoon, with money from his wife’s mother, he abandons her at a diner. In “Good Country People,” Manley Pointer (Cooper Hoffman) is a fake Bible salesman who tricks Hulga (Hawke), a woman with a wooden leg, into trusting him then steals her wooden leg and abandons her in a hayloft.

It’s not only crooks and atheists whom O’Connor skewers, but self-professed Christians, too. “Revelation,” which was the last story O’Connor wrote, deals with the self-righteous Mrs. Turpin (Laura Linney), who, judging herself to be superior to everyone else she sees in a doctor’s waiting room, is brought back to reality after being violently assaulted by grace — literally, Mary Grace (Hawke), to be precise.

To provide a thread of continuity, in Wildcat, the young female roles in each story are played by (Maya) Hawke, while the older female roles are played by Linney, who also plays O’Connor’s mother, Regina. This invites the audience to consider the extent to which these matronly characters — many of them grotesque — were inspired by tensions the real O’Connor may have had with her own mother. This suggestion is perhaps clearest in “Everything That Rises Must Converge,” which O’Connor wrote about a son whose mother has a stroke after he bitterly admonishes her, but which in Wildcat is played with Linney as the mother and Hawke in men’s clothing.

But this, too, is underdeveloped. And not least since Hawke’s O’Connor appears to have tension in all her relationships. Her publisher asks whether she’s trying to “stick pins” in her readers. He asks her to write an outline, and she responds, “I’m not writing a conventional novel.” She has “what the Freudians would call ‘anti-angel aggression.’” There’s the romance that never quite blossoms with Cal Lowell (Philip Ettinger), based on Robert Lowell, with whom O’Connor had a written correspondence.

In Wildcat, O’Connor often comes off as sulky and difficult. When her aunt complains that a story of hers “left kind of a bad taste in my mouth,” O’Connor replies: “You weren’t supposed to eat it.”

Hawke’s O’Connor gets on best with the priest, played by Liam Neeson, in a scene that adapts writings from her prayer journal. She tells him, “I long for grace. I see it, I know it’s there, but I can’t touch it.” (From her journal: “Give me the grace, dear God, to adore You, for even this I cannot do for myself. Give me the grace to adore You with the excitement of the old priests when they sacrificed a lamb to You.”)

O’Connor understood religion to be the cross. As she tells the priest: “God finds us in the darkness.” After stumbling around, Wildcat lands on grace.