The Reverend Billy is a tall, sweaty preacher in white loafers, a white suit, and a clerical collar. Though his voice sounds only vaguely Southern, his act is pure gospel revival — the quavering intonations of the sermon, the trembling body, the shout-outs from the congregation, and the improvisational feeling of the lines he shouts over the refrains sung by his green-robed gospel choir.

Rev. Billy (the alter ego of the performance artist Bill Talen) presides over what he calls the Church of Stop Shopping, which preaches that Wal-Mart consumerism is rapidly destroying our towns, our democracy, and our souls. The Church’s congregation can loosely be defined as all his troupe’s audiences, past and present, at everything from performances at alternative venues to demonstrations on the premises of the Disney Store, Victoria’s Secret, and Starbucks. (Not long ago, Mr, Talen was arrested for trespassing at a Starbucks in Astor Place.)

Whether marching in the streets, or holding forth on a stage, as he did Sunday at the Highline Ballroom in the meatpacking district, Rev. Billy’s medium is political theater. In his latest revue-style show, “The Reverend Billy’s Hot and Holy Highline Revival” (directed by Savitri D), he revisits plenty of the songs in his anti-consumerism hymnal, backed by two dozen terrific choir members and the six-piece Not Buying It Band. He also unveils a new sermon (read: monologue). It’s an uneven show, but an unexpectedly memorable one.

The show’s basic format — using the trappings of right-wing evangelism as a vehicle for left-wing protest — is a joke that quickly loses its luster. Fortunately it has the good sense to hastily shift its emphasis away from camp and toward serious themes. This is a highminded affair, albeit leavened with song, dance, smoke machines, and purple and yellow spotlights.

A jubilant opening number sets the mood for a skewered gospel brunch. “Alleluia, we will never shop again!” proclaims the choir, as three of its members jump forward and start a peppy unison dance line. Rev. Billy walks through the crowd, laying hands on people — ineffective as a joke, but curiously effective as a way of involving the audience.

Once onstage, the reverend ambles his way through his speeches with the slightly off-kilter, off-thecuff air of an overwrought gospel preacher. At times, seized by the spirit, he collapses onto the choir. At first, these skits have the whiff of a stand-up comedian’s desperation, but thankfully, the Not Buying It Band bails him out.

The groovy, jazzy band, ably led by E. Katrina Lewis, is one of the show’s greatest assets. The toe-tapping gospel tunes, mostly composed by William Moses, are solid enough musically that they can overcome some weak lyrics and an iffy book (mostly by Mr. Talen).

The one thing gospel demands is passion, and these singers have it in spades. Just watch the shockingly talented Adetola Abiade sing “Sidamo,” an anthem about the plight of Ethiopian coffee growers, and you’ll be a believer. Ms. Abiade’s rich, plaintive voice fills every pore of this nouveau spiritual, coaxing every ounce of feeling from the notes.

Ironically, the show’s biggest problem is the fact that for its first half, its theology is a bit murky. While the reverend bashes consumerism, we stare at the Highline Ballroom menus, with their $12 drinks and $24 entrées. Gradually, it emerges that the Church likes small neighborhood businesses just fine, even if they’re overpriced. It’s the giant conglomerates that the Reverend sees as destroying community and abusing the little guy.

But we don’t fully appreciate Rev. Billy’s capacity for insight until his sermon, which arrives near the end of the two-hour show. In what seems at first like an unstructured riff, the reverend makes a surprisingly affecting parable from a recent episode of “American Idol,” on which a digital Elvis and a live Celine Dion sang a ballad, but never acknowledged that the song’s lyrics were drawn from the writings of Martin Luther King Jr. Using King’s “dream” to promote the “dream” of stardom sold by “American Idol” strikes the reverend as “re-branding the most important dream that we can dream about.”

There may be sadness around the eyes of the weathered Rev. Billy, who dares pit his unamplified voice against the mighty strength of “American Idol.” But his vision of the world isn’t all fire and brimstone. There’s jubilation at this revival: the merry enjoyment of David taking on Goliath.

Until July 29 (431 W. 16th St., between Ninth and Tenth avenues, 866-468-7619).