A troubled young man whose life changed for the better after he joined a fast-growing Southern Baptist megachurch in a small town in Texas interprets one of his pastor’s sermons as a personal call to kill the husband of the pastor’s estranged son.

The young man’s aim is less than perfect and he wounds his intended victim but fatally wounds the couple’s adopted daughter before killing himself. That’s the set-up for playwright Dewey Moss’s confrontational drama, “The Crusade of Conner Stephens,” which ran off-Broadway last summer and is being presented for the first time in Hawaii.

It is the day of the murdered girl’s funeral. Family members are convening at the home of Jim Williamson Jr. (Justin Strain), aka “Junior,” and his wounded husband, Kris Thompson (Thomas Smith). Kris’ supportive sister, Kimmy Jones (Amrita Malik) and her equally supportive husband, Bobby Jones (Berkley Spivy) have already arrived. They’re joined by Junior’s quietly hostile anti-gay mother, Marianne Willamson (Amy K. Sullivan), and Junior’s acerbic grandmother, Grandma Vivi’n (Ann Brandman).

Last to arrive is Junior’s homophobic-because-that’s-what-the-Bible-says father, Big Jim Williamson (Eli K.M. Foster), the pastor whose sermon inspired Stephens to embark on his murderous mission.

Big Jim is there only because he thinks it would look bad if he wasn’t. Marianne generally feels the same way.

The family gradually dissects their unbridgeable differences as they wait for the cars that will take them to the cemetery. They dig deeper and more painfully when they return.

Playwright Moss reveals the philosophical foundation of Big Jim’s beliefs in a pivotal scene where the audience becomes the congregation as Big Jim preaches from a bible passage in Romans 1 that condemns homosexuality as being against God’s law. Foster develops the scene into a portrait of sincere but horrifying religious fanaticism.

Brandman, who looks too young to be playing Big Jim’s mother despite wearing a bright white wig, delivers the old woman’s snappy zingers as bright shots of comic relief. TAG veteran Smith gives an expertly detailed performance in another key scene.

Moss writes in the playbill that he was raised a Southern Baptist in Texas and was reviled by almost everyone he knew when he came out as gay in his late teens. There’s no question that at least part of this story is his story, and he leaves no wiggle room in deciding who the villains are.

However, the preaching scene is a reminder that people we could never agree with can be just as sure of the rightness of their world view as we are of our own.