AT FIRST GLANCE, "Tent Meeting" resembles the lovable "Greater Tuna." Both plays are makework, devised by actors to keep themselves working -- in roles tailored to their talents. Both feature a stable of unstable Southerners. Sadly, the resemblance stops there.

"Tent Meeting," at the Terrace Theater, aims to satirize fundamentalist evangelism. But this dawdling, drawling comedy manages to be both rude and timid at the same time, pulling most of its faintly blasphemous punches and lamely lampooning its sitting- duck target.

Playwright/actors Levi Lee, Larry Larson and Rebecca Alworth Wackler have set up the flip side of "Rosemary's Baby." A deformed child (who, we're told, has no limbs or vital organs) is born by apparent virgin birth to a drab hick named Becky Ann Tarbox, who happens to be the daughter of a blood-and-thunder preacher known as Reverend Ed. There's also a brother, the whiny, lumpen Darrell, who may or may not be a Vietnam veteran.

The three abduct the baby from the authorities in Arkansas and head for Moosejaw, Saskatchewan, in their claustrophobic trailer home, planning to establish a profitable religion around the child, whom they name Jesus O. Tarbox.

Meandering toward the vague conclusion of this frail setup, the Tarboxes receive a series of cryptic typewritten letters from God, manifested as an extraterrestrial Federal Express service: The missives materialize in a tumult of light and sound -- and Becky Ann has to sign for them. That's funny.

There are also a series of unpleasant jokes about the misshapen creature, and far too many empty stretches inflated by timewasting actorish embroidery. Not funny.

The less-than-novel message at the play's core is Ed's assertion that "it don't matter what the truth is -- it only matters what you believe." And the plot isn't so original, either: There are echoes of "Coyote Ugly," "Agnes of God" and "Last Days at the Dixie Girl Cafe" atop the similarity to "Greater Tuna."

The cast members are little more than adequate in their self-penned roles -- and they've created oddly colorless characters at that. Larson uses an interesting semantic tic to define Darrell, inserting variations of the phrase "which it is" into most lines. The wan Becky Ann, played by Wackler, gets her laughs by stuffing her ears with oversized wads of cotton and humming atonally to herself (in tune with heavenly music only she can hear). White-maned Lee is convincing as the Bible-thumping tyrant Reverend Ed, predominantly because of his stature.

It's a head-scratcher how "Tent Meeting" won accolades at this year's Spoleto Festival and the Humana Festival of New American Plays in Louisville, but that may help explain its presence at the Kennedy Center.

Perhaps if it were performed on a smaller stage (which it ain't), this stuff would make it (which it don't). But as it is, the Tarbox trailer looks like a postcard, and the limited reach of this "Meeting" is further diminished by the size of the Terrace Theater. TENT MEETING -- At the Kennedy Center Terrace Theater through September 14.