If Sonia Johnson could have one wish, it would be, she says, "to get the church out of politics and get it back into religion."

"The church," for Johnson, is the Church of Jesus Christ of Latter-day Saints, commonly known as the Mormons, in which her family has been active for five generations. The politics that she contends the church is enmeshed in are efforts to defeat the Equal Rights Amendment.

Because of Johnson's criticism of her church and its leaders as head of a group called Mormons for ERA, the Loudoun County woman faces a church trial -- and possibly excommunication -- this Saturday.

The preparations for the trial, the anguish over the controversy, the comings and goings of reporters and photographers and the incessant telephone calls are all taking their toll on the Johnson family.

"We are pretty much on edge," Johnson said. "I notice that the kids are crying more and they're getting pretty resentful that I'm always on the telephone."

Johnson's trial began Nov. 17 -- a closed-door session in which she met with her bishop, or congregational leader, and the two other members of the so-called bishop's court of her Sterling Park ward, or parish.

But after five hours, Johnson persuaded the bishop to postpone the actual trial for two weeks to give her time to prepare her case and summon witnesses to testify in her behalf.

The Johnsons have three children at home, but their eldest son, 16-year-old Erik, is living in Logan, Utah, with his mother's brother's family, "because of the pressures here," according to his father.

"You want to know something ironic?" volunteered Richard Johnson, who supports his wife's stand. "He (Sonia's brother) is totally against ERA and thinks Sonia ought to be excommunicated."

All of the children, he said, "are feeling the pressure." To ease things somewhat, he and the children have been attending a church in nearby Hamilton instead of their own Sterling Park ward, as local Mormon churches are called.

The criticism of their mother "got very difficult for them," she said.

But Sonia continues to serve as organist for the Sterling Park ward and as a teacher in the Relief Society, the church's women's auxiliary.

She admitted that although she teaches from a church-prepared syllabus, "on occassion, some of the women have complained to the bishop (the congregation's leader) about my lessons, because I sometimes sound too feminist."

But if the women object, she said, "they don't tell me; they just tell the bishop."

Like many churches outside the mainstream of conventional Christianity, the Mormon Church has a culture of its own, with a strong sense of belonging to the extended family of the local congregation.

The church demands a great deal from its members in both time and money -- the Johnsons follow the church's strong recommendation that they tithe, or give 10 percent of their income to the church.

But at the same time, members feel they can turn to the church when they are in trouble, no matter what kind.

Some church members brought the Johnson family a hot meal on a recent night when Sonia was unable to fix dinner because whe was too tied up with her case.

And when attorney Mike Barrett, a member of Johnson's ward, learned that she had been summoned to the trial, he volunteered to advise here.

Barrett, who is a convert to the church from Judaism, said he thinks Johnson is "dead wrong" about the ERA, but also thinks the church is wrong in putting her on trial.

"I feel very strongly that this shouldn't be happening," he said at the beginning of the trial a week and a half ago.

Johnson was unable to estimate how much the trial is costing her, though she acknowledged that the long distance telephone bills have been "horrendous." s

Tucked in with the four-page, mimeographed November newsletter of Mormons for ERA is a little note encouraging the 500 persons on the mailing list to send contributions to the Support of Sonia Committee, at a Salt Lake City address. The money is being raised to bring Utah witnesses here for the trial on Saturday.

Johnson, who has her doctorate in English education and has taught at half a dozen universities around the world, maintains she is relatively new to political activism.

"I'm really a baby feminist," she said. "I didn't know what the ERA was all about until the church came out against it."

When she studied the question, she found that she disagreed with the church.

Johnson claims that the church has organized to fight ERA. "What is reprehensible is that they (groups of church members) do not tell anyone that they are Mormons" when they lobby against the ERA in state legislatures. "They go down and say that they're just private citizens and the legislators think, 'Gee, there's a lot of grassroots opposition to this.'"

Commenting on what she said were church-directed lobbying efforts against the ERA in Illinois, she observed: "If the legislators in Illinois knew that men in Salt Lake City were controlling the politics of Illinois, they'd be furious."

Mormons, she charged "want to decide the morality of the whole country."

Leaders of the Mormon church, which is governed by a male hierarchy, have spoken out strongly against the ERA and church members have been active in efforts to defeat it. Church spokesmen, however, insist that members are free to follow their own consciences on the issue.

Locally, leaders of the church have declined to comment on the Johnson case, on the ground that what transpires in a bishop's court is as confidential as a confessional.

Johnson has charged that she is now in hot water with her church because "we [Mormons for ERA] are being too effective" in opposing the church's stand on ERA.

Excommunication is a particularly grave step for a Mormon. They believe that church members who are married in the temple -- as the Johnsons were -- and who fulfill the prescribed rituals are bound together throughout all eternity and earn a choice place in heaven.

While excommunication would not affect the civil aspect of the Johnsons' marriage, it would shatter their celestial relationship. It would separate her from her husband and children for all eternity, according to the church's teachings.

Excommunication in the Mormon church can be overcome through repenting and being baptized again, but Johnson says she has "nothing to repent of."

The night before she first appeared before the bishop's court, her bishop, Jeffrey Willis, and his aides appeared at her home and asked for her temple recommend, a coveted church document that attests to the member's faithfulness. Without one, a member may not enter the church's temple in Kensington, Md., to perform church rites.

"When they demanded my temple recommend, I felt like I'd already been found guilty, without ever having a trial," Johnson said.

The actions of the bishop's court are almost never made public and Johnson knows that she is infuriating church leaders by discussing her case so openly.

But she says she doesn't have much choice. "When you can't be heard by those in power, you take whatever help there is."