Distressed by what they see as a decline in America's moral values, several leading fundamentalist preachers are attempting to organize the nation's Christian population into a new and potent political force.

Within the past few months two new organizations have sprung up at opposite ends of the country, seeking to enlist the support of what some activists estimate to the the nation's 75 million right-leaning Christians -- everyone from Mormons and Southern Baptists to conservative Roman Catholics, they say.

These groups -- the Washington based The Moral Majority, and Christian Voice, headquartered in Pasadena, Calif. -- have already initiated mass mailing campaigns, produced television ads and begun raising money to fund a number of lobbying efforts. Goals include tax breaks for church-run schools, diplomatic recognition of the new government of Zimbabwe-Rhodesia, and the frustration of the abortion and gay rights movement.

The Rev. Richard Zone, an evangelical preacher from Glendale, Calif., believes Christians are fed up with the liberal permissive policies of the political establishment. They are prepared, Zone says, to lobby for legislation and support candidates who espouse what he describes as "godly positions."

"This country is on a downward moral spiral," Zone, operations director for Christian Voice, says. "It's going so bad that Christians who didn't want to get involved are getting involved. They see society becoming completely godless. There's danger and a sense of urgency now."

Zone says his organization already has more than 100,000 members and will spend nearly $1 million this year to spread its conservative Christian message. Nearly 1,500 clergymen, he adds, have joined Christian Voice, including nearly 300 from the Catholic church.

The Moral Majority, formed only this June, is seeking a similar constituency. Led by Dr. Jerry Falwell, an evangelical preacher from Lynchburg, Va., the Moral Majority is working to unite the nation's religious conservatives into a coalition capable of steering America away from liberal, humanist and secular tendencies.

Falwell believes there is a "trend in a political direction" running throughout evangelical, fundamentalist and hardline Catholic circles in the United States. He argues that differing religious groups, long at each other's throats, are now putting aside their doctrinal conflicts to battle common foes.

"Religious organizations are marching together who never worked with each other," said Falwell, host of the "Old Time Gospel Hour" seen on more than 300 television stations nationwide. Evangelicals, fundamenalists, conservatives, Catholics and Mormons are all working together now."

The Moral Majority has gathered most of its support, according to Falwell, from some 300 ministers, for the most part Baptists, across the country who ahve agreed to preach the group's message to their congregations. Christian Voice, meanwhile, has worked hard to win support from leaders on Capitol Hill and has set up a congressional advisory board.

Christian Voice's board includes Sens. Orrin G. Hatch (R-Utah), Gordon J. Humphrey (R-N.H.), Roger W. Jepsen (R-Iowa), as well as California Republican Congressman Robert K. Dornan, Georgia Democratic Representative Larry P. McDonald and nine other members of the lower house.

Both organizations plan to make extensive use of the "electronic church," the various Christian programming networks, which claim as many as 40 million regular viewers. Organization leaders have already started placing their spokesmen, including some of the congressmen, on appropriate shows to reach the mass television audience.

Christian Voice and The Moral Majority also expect to lobby Congress extensively during the next session on such key issues as abortion, gay rights and Zimbabwe-Rhodesia. Neither group, in addition, rules out the possibility of endorsing candidates in the 1980 election, including presidential contenders like former California governor Ronald Reagan, or former Texas governor John Connally.

This interlock between religious fervor and practical politics disturbs many leaders of more established religious organizations and those involved in the movement for homosexual rights. These people tend to see groups like Christian Voice and The Moral as cynical attempts to transform honest Christian faith into right-wing political action.

"They claim they will finally get us Christian representation in Washington but I think that shows considerable arrogance," says the Rev. Charles Bergstrom, executive director of the office for governmental affairs of the Lutheran Council U.S.A. "My concern is a theological one. It's bad theology to describe one organization as Christian. There are many Christians and its impossible to talk about one point of view representing Christian views."

Other religious leaders fear the new groups could serve as shelters for racism, reaction and intolerance within the nation's political life. Even one of Christian Voice's congressional supporters, Rep. Dornan, a staunch Catholic, has publicly urged the organization to disassociate itself from what he fears are "anti-Semitic" tendencies among its membership.

Doran's concern is shared by Jewish community leaders wary of any infusion of fundamentalist Christian fervor into the political process. David Lehrer, spokesman for B'nai Brith's Anti-Defamation League in Los Angeles, says Christian Voice, while potentially dangerous, may well fizzle out before doing any real damage.

"Our feeling is it's more hype than anything else," Lehrer says. "We are of course concerned, but we don't want to help them generate any more publicity."

Lehrer's relaxed attitude is not shared by Adam DeBaugh, director of the Washington office of the Universal Fellowship of Metropolitan Churches, a predominantly homosexual activist church denounced by fundamentalist Christian leaders.

DeBaugh says groups like Christian Voice pose a direct threat to gay, minority and all other "oppressed" people. "They are using Christianity as a facade for a political organization," DeBaugh said. "All their policies are blatantly sexist and racist. They appeal to the worst things in people. It's a misuse of Christian thought."

Defenders of Christian Voice, such as Sen. Hatch, insist fundamentalists and other conservative Christians are simply making up for a lack of representation of their views in such traditionally liberal, mainstream Christian organizations as the National Council of Churches.

"The other side has been working too long without opposition," says Hatch, a devout Mormon. "I don't see why a good group of moral, honorable Christian people like these should'nt get involved. They should encourage people to vote for people with Christian principles. Why shouldn't they get into any kind of politics they want?"