Three years ago, the Fairfax County Republican Party, Virginia's largest local GOP organization, held seminars on "Christians and the Electoral Process" and "getting godly candidates." That was after the Christian Right had purged mainstream Republicans from the party's governing central committee.

Today, moderates run the local Republican Party, having sacked conservative party Chairman Benton K. Partin in 1986. The last of Partin's allies in the Virginia House of Delegates is retiring, and, with the exception of a few activists outside the political mainstream, there is little talk anymore of recruiting "godly candidates."

Further, the Christian Right in Fairfax was dealt three defeats in one afternoon last week when the county's Board of Supervisors refused to banish clubs featuring topless dancing, turned down a proposal to build a for-profit Christian school in Oakton and declined to interfere with Fairfax Hospital's policy of performing abortions.

"I think {the Christian Right has} peaked out around here, and it's probably true nationally, too," said Jeremy F. Plant, associate professor of public administration at George Mason University in Fairfax. "What's happened recently in Fairfax County is probably an indication that they're too far from the center to be decisive."

According to interviews last week with political sources in both major parties, scholars, clergy and Christian activists, the influence of fundamentalists and other politically conservative evangelicals in Fairfax is in decline.

Those interviewed said Fairfax's Christian Right has lost influence for a number of reasons, including:

An agenda focused on social issues that is muffled by the increasingly fervent political debate about traffic and development in the suburbs.

A reluctance by many, perhaps most, clergy to descend from their pulpits into the more ambiguous realm of local politics.

Leaders who tend to be more politically extreme, and at times vindictive, than their followers.

A continuing reaction to the earlier purge of moderate and mainstream Republicans by the Christian Right. That event energized the mainstream party stalwarts, who responded by ousting Partin three years later.

Moreover, the political slippage of the Christian Right in Fairfax appears to mirror a national phenomenon, although the final judgment on that question may await the outcome of the Republican presidential campaign of television evangelist Marion G. (Pat) Robertson, according to political observers.

In a Gallup poll taken in April, 29 percent of the respondents said they would be less likely to vote for a candidate who considers himself a "born-again" evangelical Christian, about twice the number of those who said they would be more likely to vote for such a candidate. Fifty-two percent said it would make no difference.

The Gallup results represented a major shift from 1980, when 19 percent of the respondents said they would be more likely to vote for an evangelical, and 9 percent said they would be less likely. Sixty-six percent said it would make no difference.

Quantifying the strength of the Christian Right in Fairfax is pure guesswork. The county has 380,000 registered voters, of whom about 114,000 consider themselves Republicans, according to a recent survey by the county Economic Development Authority. Anywhere from 15 percent to 50 percent could be considered Christian Right, depending upon the issue or the definition, according to political observers.

After last week's setbacks, one Fairfax Christian Right activist said he planned to mobilize more than 200 religious leaders in the county to urge their congregations to get involved in campaigns for the state legislature and county Board of Supervisors before the Nov. 3 elections.

The activist, Richard J. Enrico, is executive director and founder of the Foundation for Moral Restoration, a Fairfax County group. Enrico's last major crusade was to persuade some drug stores, convenience stores and hotels in the Washington area and other states to stop selling sexually oriented magazines.

Enrico said churches have no business complaining about political defeats if they do not get involved in election-year politics. "They're more busy with Bible studies and potluck dinners and Christian discussion groups," he said. "They're not using their God-given right to vote."

Enrico said he plans to recommend that pastors single out the members of their congregations who do not vote, a tactic he acknowledged might "shock" the laity.

Despite Enrico's reputation as an effective organizer, the odds appear to be against him. For one thing, many ministers appear wary -- if not altogether unwilling -- to involve their churches in local politics. One example is the Rev. Bill Kynes. Kynes, who has organized three marches at Fairfax Hospital to protest abortion, said that while he feels duty-bound to speak out on that issue, he is not willing to get involved in partisan politics.

"The nitty-gritty of politics is different from protesting abortion," said Kynes, the 31-year-old pastor of the National Evangelical Free Church in Annandale. "I don't want the church I am associated with to be seen as just another special-interest group. I want to be able to stand above politics and speak prophetically from an independent perspective, and bring to bear the truth of God's revelation . . . . "

Said Bill Wheaton, director of the Fellowship of Christian Educators, an informational group in Fairfax: "Unfortunately, there are very few pastors who are courageous enough to stand up in the pulpit and challenge their congregations in these areas."

The decline of the Christian Right's influence does not mean the group is powerless. Some Northern Virginia Republicans, notably U.S. Rep. Frank R. Wolf and Fairfax County Board Chairman John F. Herrity, are assiduous patrons of conservative and Christian causes and lend a sympathetic ear if asked.

Last week, for example, Herrity lost his temper during a closed-door session of the Fairfax board when some supervisors said the county should ignore the pleas of a conservative Christian lawyer who wants the board to attempt to halt abortions at Fairfax Hospital.

According to several board members who were present, a disturbed Herrity said that one prominent conservative, Lawrence D. Pratt, had threatened to send a letter on the abortion issue unless Herrity took action. The letter, according to several sources who have seen a draft, faults Herrity for failing to try to halt abortions at the hospital. The county attorney has ruled that the county board has no such authority. After some discussion, the board declined to interfere with the hospital.

Pratt is executive director of Gun Owners of America, a Washington-based organization that strongly defends the right to bear arms. He did not return phone calls.

In some primaries, where small numbers of motivated voters can have a big impact, conservative Christians are still able to flex their muscles if the right mixture of issues and candidates is present.

In June, for example, Lloyd Thoburn, the 25-year-old son of a conservative former state delegate, came close to knocking off Supervisor Nancy K. Falck, an eight-year incumbent, in a GOP primary in the Dranesville District, which borders the Potomac in northern Fairfax.

Thoburn, the administrator of his family's Christian school, focused his well-financed campaign, in part, on the churches that dot the Rte. 7 corridor from Tysons Corner to the Loudoun County line. Some of those churches were angered when their expansion plans were denied by county officials, citing potential traffic problems.

Robert Thoburn, Lloyd's father, is running as an independent candidate against Falck. The senior Thoburn, a Christian whom former Virginia lieutenant governor Henry E. Howell once called "the Siamese twin of a caveman," is given little chance of winning in the November election.

"There's a lot of potential for political power for Christians, but it's asleep," said Wheaton of the Fellowship of Christian Educators. "Liberals have made a lot of Christians question whether it's spiritual to get involved in politics."