Marybeth Wetzel had tried three times to quit smoking before her latest attempt, before she paid $300 and locked herself up with a dozen other lost souls in a mountain resort and let a religious group try, through a combination of fear, faith and fruit juices to help her kick a four-pack-a-day habit.

This time, though, there was a motivation lacking in her previous attempts.

"I was tired of being hounded," she said. The big no-smoking sign that one member of her car pool had placed prominently on the dashboard had been bad enough. But it was the amateur theatrics of one of her colleagues that finally drove her up the wall.

"That young woman made it so hot for me," Wetzel said. "She would wave the air, and gasp and talk about her an aspirin and pretend that it wasn't aimed at me. But the pressure just gets very, very uncomfortable."

It's not that Wetzel approves of such tactics. "I don't think those people should know how effective they are," she said. "They've been brainwashed into thinking they can be as obnoxious as they want because their case is just. I don't want to give them any encouragement."

Popes have tried excommunicating smokers to make them stop and emperors have resorted to a variety of techniques that included nose-slitting, flogging, and banishment. The surgeon general tried scaring everybody to death and neatly printed little warnings, HEW Secretary Joseph A. Califano Jr. wants to educate people out of their "slow-motion suicide." Now, it seems, the thumb-screws of social pressure may yet accomplish what other, less serious threats to the habit have not - changing the thing that has always mattered most about cigarettes - their image.

There are times now when smoking cigarettes seems to have the same social cachet as picking one's teeth.

The outward sign of this social disapproval appear with increasing frequency - a conspicuous absence of ashtrays in a growing number of offices and living rooms, a ripple of cultivated cringes away from a transgressor in a busy restaurant. "I started smoking so I wouldn't feel stupid at parties," said one woman as she toyed with the low-tar-nicotine-recessed-filtered vestige of what used to be a two-pack-a-day Camel habit. "Now I feel like an idiot, sneaking around putting out my cigarette in the nearest potted palm."

Smokers sit in the back of the bus now as well as planes, and over 30 states have some form of legislation banning smoking in various public places. The Tobacco Institute, the industry's powerful lobbying and public relations arm, calls the growing strength of anti-smoking forces one of the most powerful threats they have had to confront since the Surgeon General's report in 1964.

It was not always so.

Once, smoking was exciting, daring, darkly sophisticated. It was Bogart and Bacall, wreathing their romance in hazy gray-blue glamor. It was a way to arch an eyebrow at strait-laced proprieties, it was the ultimate social prop.

With the aid of advertising and th ecooperation of the public imagination, smoking has managed throughout the years to symbolize any number of subterranean longings in the human soul, a habit transcending economies, ideology and the most dire intimations of mortality.

The lighting, sharing and smoking of cigarettes provided a kind of sexual shorthand for generations of cinematic lovers, the most visible symbol of Bette Davis' deliverance from a sheltered spinsterhood at the hands of Paul Henreid in "Now, Voyager." James Dean's rebellion smouldered though them and a cigarette was as much as essential to a lawman's proper pursuit of his criminal quarry as a sure aim and a lack of facial expression.

In the end, cigarettes provided a kind of cultural dichotomy that was more expressive than any of the other usual us-them divisions - Republican-Democrat, young-old, UHF-VHF. "I always thought smokers weren't as hidebound, as conservative, as non-smokers," Wetzel said. "I always considered non-smokers to be religious, stuffy, and dull." She paused, thinking back on the 30 years she smoked, and the year and a half she hasn't. "I still do."

But now, Woody Allen and Diane Keaton in "Annie Hall" begin their romance on a tennis court and end it in a health-food restaurant. Dean has dissolved into the Fonz, and Kojak sucks a contemplative lollipop while puursuing his version of criminal justice. Righteous Aggression

Now, there are otherwise perfectly tasteful cars traveling the nation's highways with bumper stickers that say "Kissing a Cigarette Smoker is Like Licking a Dirty Ashtray," and the world seems rapidly to be dividing into increasingly militant factions of smokers, ex-smokers, non-smokers, and anti-smokers.

Last year, a woman in a local restaurant doused a man with a glass of water after he refused to put out his cigar. He, in turn, followed her five blocks and found a policeman to arrest her for assault.

A Florida high-school teacher was charged with battery after he sprayed two colleagues with an "ammonia-like" liquid after they lit up during a coffee break.

Meanwhile, in Elko, County, Nevada, a state law requiring no-Smoking signs in hospitals didn't sit well with local officials, who put up the required sign in Hebrew.

In Fairfax County, they take such legislation much more seriously, as Edythe Gaisor found to her dismay. Gaisor lives amid the quiet affluence of suburban McLean and considers herself a "respectable, middle-class type person," who does respectable, middle-class type things, like playing bridge and paying taxes.

Certainly not the type of person, in any case, who expects to find herself hounded from her local community center, her bridge club disbanded and threatened with police action. All of which did happen when Gaisor and her fellow card players lit up in the community center after Fairfax passed an ordinance banning smoking in public places.

"We're nice middle-aged people," Gaisor said sadly. "We didn't burn holes in the curtains or anything and we were the only people using the center at that hour." It's getting to the point, she said, where "you're made to feel like a criminal or something" for smoking. Upper-Income Quitters

So far, it seems, it is the educated middle class that is smoking less, the same people who made a fad out of an early-morning run to nowhere and who keep hoisting diet books and assertiveness training manuals on to the best-seller lists.

Statistics say that more ex-smokers are to be found in the upper-income brackets, among the ranks of white college-educated males, just the sort of people to start a trend out of giving up a habit.

Cigarettes are still the first luxury item poor people buy, according to the U.S. Agriculture Department, and it's one of the last necessities anyone will surrender. Depending on what study is consulted, smokers tend also to be less married, more neurotic, less inclined to look to the future, more inclined to leave large tips. Many of them are teenagers.

Christie is apple-cheeked and 12 and chainsmoking Marlboro and practicing the standard teen-age scales of slouching and sullen expression at Tysons Corner shopping center. She started smoking for the same reason Wetzel quit - peer pressure. That's not how she puts it, of course. "My mom hates it," she said. "And my friends think it's cool."

It's strong stuff, the desire to be cool, about as instinctive a yearning among the young as hunger or thirst among these of a less trying age. Consequently, said Milton Robertson, director of Audio-Visuals for the American Lung Association, "We're trying to uncool it," concentrating the pitch on smoking as socially unacceptable rather than merely unhealthy.

"Death, doom and disaster just doesn't work," Robertson said. "At 16, you're convinced of your own immortality. What does it matter that you might get cancer when you're 40? At 16, 40 is forever." Fallen Crusaders

This latest crop of adolescents was born well after the first Surgeon General's report on smoking. Many of them, while still in the adorable stage, were some of the most energetic crusaders ever recruited into the antismoking cause through the public service commercials they absorbed on daytime television.

Now, many of them have joined the growing number of teen-age smokers, swelling what Califano calls "one of the most frightening" statistics among the unredeemed.

Thus one of the few government-funded, anti-smoking projects is aimed at teen-agers, trying to turn them off to cigarettes by the way of biofeed-back in New Hampshire - where students can test themselves to see the effects of a single cigarette on their bodies - to assertiveness training in Buffalo - where they can learn the techniques that will fend off the perennial hoodoo of social status.

Finding the right role models for such campaigns, however, can be tricky in itself. "Once we tried to do a campaign where well-known athletes would do some PSA's (public service announcements)," Robertson said. "But we discovered that most of the ones we wanted smoked their lungs out."

If role models fail, there is always revenue psychology. "We try to get across that it's more independent not to smoke," said Beverly Schwartz, co-ordinator of the federally funded project. "That you show more macho if you don't let yourself get pushed into it." Stages of Mourning

For those trying to claw their way out, the process can be as ambivalent as the ending of many another love affair, even after one has passed through the stage of feeling like an amputee victim and is merely mourning the loss of a beloved companion.

Six months ago, the writer decided it was time. Time to unwrap the ego from the smoky tendrills that seemed to curl around and absolve every need. Time to face the world uncomforted, that is unencoumbered by the talisman of tobacco. Was there life without cigarettes?

Time passed and life's small crises were overcome. Deadlines were met, cocktail parties confronted, disappointment endured. Perhaps a grace note was missing here and there, but maybe that's what life among the elect was like.

It was a good decision. It was the right decision. Friends approved smilingly, three was renewed kinship with innocence. Best of all, what was once a habit was now a sin and more tempting than ever.

The ex-smokers enters a bar with a friend, their friendship strengthened by the travails they have suffered while giving up cigarettes and in the eulogies they regularly say over its exit from their lives.

The bar is dark and hazy, the juke-box is playing, the casual camaradeie of days' end is poured into the evening, ice cubes cling in the glass and the friend pulls out a cigarette. It is the ultimate berayal.

"WHAT ARE YOU DOING? shrieks the ex-smoke to her friend."Do you know what those things can do to you? Do you know that you lose five minutes of your life for every cigarette that you smoke? Think of the dark shadow passing over your lungs, think of the discipline dissolved in the ashtray, think of your veins filled with this horror, think of me!"

The friend smiles tolernantly, looking more like Faye Dunaway in "Chinatown" every mminute. A non-smoker at the table looks bemused. The conversation drifts with the smoke, witty, sophisticated, bon mots dropping with each casual flick of the ashes.

They said the first puff after six months would be terrible. They lied. The mea culpas will come with the morning coffee.