Marty Feldman's film directing career was based on a misunderstanding much funnier than any situation in his two facetious abominations, "The Last Remake of Beau Geste" and the new release "In God We Trust, or Gimme That Prime-Time Religion." When Feldman suggested a spoof of "Beau Geste" to Universal, which owned the rights, he had the story confused with "Four Feathers," which depicts another sort of beau geste .

Discovering his mistake after the deal was closed, Feldman wisely kept it to himself. After the movie was completed -- and became a minor hit -- the story could be told as an amusing anecdote. It rang true because Feldman might have made sense as a burlesque version of the masochistic hero of "Four Feathers," Harry Faversham, who spends most of the story disguised as a mute slave. There never was an exploitable role for Feldman in "Beau Geste," a fact he underlined painfully by casting himself as Michael York's inexplicably homely, servile twin brother.

"In God We Trust," an imbecilic satire of crooked evangelism, proves that Feldman still doesn't know what he's doing behind the camera. His sense of humor is once again exposed as outmoded and mawkish, his technique as shabbily amateurish. Among other drawbacks, "In God We Trust" looks seedy. Indoors or outdoors, the lighting frequently seems calculated to evoke the dimmest, grungiest public toilet from which you ever hastened to escape.

Universal's recent reliance on comedy, encouraged by the success of "Smokey and the Bandit" and "Animal House," has proved rather degrading. "In God We Trust" was preceded this year by "Smokey and the Bandit II," "The Blues Brothers," "Where the Buffalo Roam" and "The Last Married Couple in America." To be fair, the studio also released "Cheech & Chong's Next Movie," a degenerate farce that did amuse me, and still has Jonathan Demme's "Melvin and Howard" in reserve. But what a far cry from the good old days when comedy was the Universal staple and meant reliable yocks with Abbott & Costello, Ma & Pa Kettle, Francis the Talking Mule, the inscrutable Maria Montez and the defenseless young Tony Curtis.

Feldman tries in vain to ingratiate himself as an innocent monk, Brother Ambrose, who is sent on a fund-raising mission by his abbot, Wilfrid Hyde-White, taken with the strange delusion that a gaudy TV evangelist called Armageddon T. Thunderbird -- ATT for short, a typical example of the blunt, harmless edge Feldman puts on his sadonation. Making his way to the nearby wicked metropolis of L.A., Ambrose is swindled by a small-time charlatan. Peter Boyle as a dipso evangelist named Sebastian Melmoth, who travels in a broken-down bus-sanctuary whose roof is adorned with a church steeple, and then befriended by Louise Lasser as a streetwalker named (tee-hee) Mary, engendering a love affair of repellent coyness.

Feldman and Lasser are not a very glamorous romantic team, to put it gently. They've also begun to look a little, uh, venerable. The idea of them sparking and reproducing leaves something to be desired, especially when Lasser, apparently obsessed with the hooker side of her character, goes on chain-smoking in an advanced state of pregnancy.

After several rebuffs, Ambrose is enlisted and exploited by Thunderbird, played with surprising wit and forcefulness by Andy Kaufman, who drops his meek persona for a robust caricature of outrageous hypocrisy that is likely to enhance his career as decisively as Ambrose subverts Feldman's. (The only effective visual joke in the film surrounds Kaufman: He's bathed in a glare of white light that makes him appear almost ethereal.) Brought to his sense by Mary and Melmoth, illogically transformed into exemplars of virtue and religious piety, Ambrose takes it upon himself to destroy Thunderbird's operation and redistribute his wealth -- in typical movie "populist" fashion by dumping a windfall of currency on bystanders from a skyscraper window).

An excruciating tone is established immediately upon entering the monastery, called The Trappist Order of St. Ambrose the Unlikely. Indeed, Feldman's conception of the comic seems to depend on witless names, labels or signs. There are signs all over the place: "Money Can't Buy You Poverty," "Silence Except When Talking to God," "Keep Thy Trappist Shut." The level of humor doesn't improve in the outside world. Thunderbird implausibly advertises his greed with office placards like "Truth Is Booty" and "The Bucks Stop Here."

Feldman's forlorn command of slapstick is revealed in the following setpiece: We see a crumbling wall upon which a sign reading "Silence" hangs by one nailed corner; Feldman enters the frame from the left and exits right; he returns, studies the dangling sign and exits left; he returns again bearing a carpetbag, from which he removes a hammer and nail; he begins to nail the opposite corner of the sign only to hit his thumb with the hammer; fuming, he places the bag over his head and emits a muffled scream; he completes the job and exits sucking his damaged thumb; the sign collapses.

Feldman seems remarkably impoverished at either visual or verbal gags. Consider the following examples of funny chitchat: "Let's run it up the crucifix and see who genuflects" or "If God didn't intend some people to be poor, he wouldn't have published the Bible in paperback."

Barring the performances of Kaufman and Richard Pryor, who turns up briefly as a merry old computer-deity, glimpsed mainly through a small porthole, "In God We Trust" is an unmitigated disgrace. What recommended material this conceptually stupid in the first place? The occasional editorializing, like the scene in which Thunderbird modulates his congregation from a chant of "Seek! Hail!" into "Sieg heil!"? A touch this bold might well appeal to the same executives who evidently regarded "The Blues Brothers" and "Where the Buffalo Room" as the iconoclastic berries.

A few years ago "The World's Greatest Lover" apparently brought Gene Wilder's fledgling directorial career to a screeching halt. Marty Feldman deserves as much, if not more merciful consideration. "In God We Trust" appears to be the work of a filmmaker secretly pleading, "Stop me, before I do it again!"