In 1980, Norman Lear experienced his first sustained exposure to the Rev. Jerry Falwell, and he did not like what he saw.

While doing research for a possible movie, Lear watched nearly 100 hours of Falwell's "Old Time Gospel Hour," the Rev. Pat Robertson's "700 Club" and other evangelical shows. He said he was so alarmed that he dropped the movie plan and made a 60-second commercial on religious intolerance. That led to the creation of People for the American Way.

Five years later, Lear's group has become a major force in the national debate on religious liberty, censorship, church-state relations and judicial independence. If yards of newsprint and hours of television time are any indication, People for the American Way has emerged as a preeminent spokesman on the left, fueled in part by a $5 million budget that dwarfs those of most liberal advocacy groups.

While its publicity machine cuts a wide swath through Washington, the soul of Lear's organization remains its fervent opposition to Falwell's Moral Majority. This has produced a remarkably bitter and personal war of words between television producer and television preacher.

"Norman Lear is clearly anti-Christian," Falwell said. "I don't know of many Jewish people who are anti-Christian. His whole vendetta is against everyone who is preaching the gospel . . . .

"I see an anti-Christian, anti-Reagan fire raging in his soul that's caused him to lash out at the president and the Pat Robertsons and Jerry Falwells of the world.

"I've tried to get the name of his synagogue so I could call his rabbi and find out what's bugging him," said Falwell, 52. "Maybe he doesn't have one. He's just got Christians in his craw."

Lear, 62, creator of such television series as "All in the Family," "Maude" and "Mary Hartman, Mary Hartman," responded in kind:

"There's nobody who knows me who thinks I'm either irreligious or antireligious. I have great concern anytime someone suggests that God smiles on him because he believes a certain way and doesn't smile on me.

"He would have to know, the way he talks about me, that . . . to an anti-Semite, a wealthy Jew is different from someone else who is wealthy. The Rev. Falwell trades in that in a consistent and smarmy fashion."

Lear's lieutenants declared a victory of sorts last month when Falwell announced that the Moral Majority was being submerged into a new lobby called the Liberty Federation. They expressed particular delight when Falwell told The Washington Times that he was "attempting to counter everything that People for the American Way . . . and other leftist organizations stand for."

How did this group quickly become the bete noire of the religious right? At a time when conservative think tanks are dominating the Washington scene with a more legalistic and academic approach to public policy, People for the American Way uses the media to amplify its message.

The 200,000-member group does some lobbying, but its major weapons are books, videotapes, op-ed page articles and speakers who ply the lecture circuit. Whether castigating Falwell for religious intolerance, Attorney General Edwin Meese III for promoting ultraconservative judges or Education Secretary William J. Bennett for acting like a "secretary of evangelism," Lear's troops know how to gain.

While other activists may churn out legal briefs or cultivate allies in the administration, People for the American Way strives to be the most well-thumbed card in reporters' Rolodex files.

Anthony T. Podesta, the executive director, said his approach is "to get an editorial in The Philadelphia Inquirer or The Baltimore Sun. We raise hell in the Chicago Tribune and on MacNeil/Lehrer. We send material to 300 radio talk shows. We're out there in the Edwardsville, Ill., Gazette."

Podesta's reasoning is simple: "If separation of church and state isn't going to sell in Edwardsville, Ill., Washington is not going to save us."

Last summer, while President Reagan was preparing to name Herbert E. Ellingwood to head the office that screens potential federal judges, Podesta's staff prepared radio advertisements that attacked Ellingwood's outspoken brand of Christian fundamentalism and his record as head of the Merit Systems Protection Board. The nomination was not made.

Such assaults have not endeared the group to conservative activists. "I don't like their tactics at all," said Patrick B. McGuigan of the Free Congress Foundation. "They're feeding the mentality that you can't oppose people on the merits, that you have to pretend that they're moral lepers."

Loye Miller, a spokesman for Bennett, called the group "so shrill and predictably distorted that they deserve no credibility . . . . They are not taken seriously here."

Falwell describes the group as "an amazingly small organization" of closet Democrats. "If they could get 100 of their members in the same room, I'd like to see that," he said.

Falwell, whose Moral Majority claims 6.5 million members, said Lear's group frequently harasses him by writing to television stations that carry his program. People for the American Way said these are equal-time requests, but Falwell called it an attempt to force him off the air.

Other critics confess grudging admiration. "You have to concede their effectiveness," Justice Department spokesman Patrick Korten said. "They manage to get themselves quoted quite a lot."

Still, he said, "It's basically a PR operation" aimed at "creating the impression that there is some groundswell out there that would support their point of view. In fact, that groundswell is largely limited to the usual residue of liberal activists."

Ticking off names of Republican supporters, Lear rejects the notion that he has assembled a group of Democratic partisans. He said he took pains "to enlist mainline church leaders" in establishing the group after nearly 10,000 people dialed a toll-free number featured in his 1980 commercial.

"My credentials . . . were all wrong," Lear said. "I was a product of the Hollywood community; I was Jewish."

Lear points to such founders as the Rev. Charles Bergstrom, a leader of the Lutheran Council, and the group's chairman, former Baptist minister John Buchanan.

Buchanan, an eight-term Republican congressman from Alabama until the New Right helped defeat him in 1980, said he signed up because "most Americans don't like for preachers to tell them what is the Christian position on an issue."

Other directors range from Catholic University President William Byron to actor Martin Sheen to National Education Association President Mary Hatwood Futrell. Lear's direct-mail specialist, Art Kropp, is a former fund-raiser for the Republican National Committee, and his latest appeal was signed by Sen. Lowell P. Weicker Jr. (R-Conn.).

Podesta, 42, admits to being a Democrat who did advance work for the 1980 presidential campaign of Sen. Edward M. Kennedy (D-Mass.) and for 1984 vice-presidential nominee Geraldine A. Ferraro.

Podesta also resists the liberal label, saying that "what we do is profoundly conservative. Conserving the First Amendment heritage in this country is not a liberal agenda . . . . The people on the loony right think we're left-wingers."

People for the American Way spent much time last year attacking the Reagan administration. It mounted a media campaign accusing Meese, Falwell and Sen. Jesse Helms (R-N.C.) of trying to stack the federal judiciary with extremists and impose a right-wing litmus test on potential judges.

It issued a scathing report on Bennett's first 100 days in office, called "A Department at Risk." It urged dismissal of a Treasury Department official who answered a citizen's post card by calling him an "amazing, pathetic creature" for questioning that America is "a Christian nation."

The group also helped defeat an amendment by Sen. Orrin G. Hatch (R-Utah) that would have ended federal funding to school districts that teach "secular humanism." And it aired a documentary on book-burning, narrated by actor Burt Lancaster, that a Moral Majority official said "would make the propagandists of the Soviet Union and the Third Reich proud."

The anticensorship campaign is slowly moving the group's focus beyond the Beltway. In 1984, it helped persuade Texas, the nation's largest purchaser of school textbooks, to repeal a rule barring the use of books mentioning evolution. In recent weeks, staffers have been flying to tiny Church Hill, Tenn., to join a battle over school curriculum.

"You look for opportunities like that," Podesta said, "so that Newsweek then does a little blurb in 'Periscope' to show that the fight against secular humanism and evolution is not yet over."

What makes all this possible is money, which Lear's group raises through a time-honored technique: painting the opposition in fearsome colors. Lear aides monitor Falwell's every utterance with a "televangelist survey" that provides fresh grist for their fund-raising mill.

Lear, in turn, is a leading character in Falwell's fund-raising appeals. While direct-mail donations to conservative causes have been declining, the Moral Majority still raised $7 million last year as part of Falwell's $100 million empire.

Lear said that, after one Falwell mailing called him the number one threat to the American family, he received death threats from a man who turned out to have the letter taped to his wall.

While many believe that Lear, a prodigious fund-raiser, bankrolls People for the American Way, he donated just $100,000 of its $5 million budget last year. Nearly 20 percent comes from foundations, with the rest from individual donors responding to appeals that rarely fail to mention Falwell.

"They use me as a whipping boy," Falwell said. "I am to them what Ted Kennedy is to the right -- I'm their means of raising money. If I were to die today, their organization would go out of business."

To that, Lear replied: "Look at his mail and how much it mentions me . . . . In his mailings, which are far more vitriolic than anything he says on the air, he suggests that anybody that disagrees with him is satanic."