I COVERED two conventions this month. One was the feminist National Organization for Women (NOW) meeting in Los Angeles, and the other was Phyllis Schlafly's Eagle Forum/Stop ERA meeting in St. Louis. I thought they would be a study in contrasts. Instead, I found myself preparing an imaginary speech I could have given at either gathering:

"This is an exciting day," I could have begun. "American women are at a turning point. The survival of the homemaker and the future of America's children are at stake. Our opponents are heavily financed, with powerful supporters, but they live in a dream world.

"They are wrong about what women want and they are lying about their goals. Their approach would reduce women to ciphers. Our dedicated grass-roots campaign, which has been so successful, has proved this time and again.The women of America merely have to be contacted and they stay with us forever. We are the mainstream!"

"I might add," I might have continued, "that President Carter has been a gutless wonder on the women's agenda. The only way he can save himself is by a total commitment to our cause."

"And in conclusion, my friends," I could have finished, "let me remind you to buy a raffle ticket for this lovely hand-made quilt you see up here by the podium."

The two women's groups are arch-enemies, each viewing the other as littles less than a menace to the republic. Yet both groups share worries about the American family that they are working hard to make the issues of the 1980s.

Given their uncannily similar Logic, their grim dedication and growing political savvy, they are clearly going to be fighting on an increasingly larger stage.

"We never used to be political," said NOW president Eleanor Smeal in an interview before the convention. "It took us from 1968 to 1977 to form a political action committee. Politics was male-dominated, 'not nice, not clean.' No more."

Women, she said, used to be afraid to speak up in public. "That made us apolitical. Now we see that what women get paid is a political issue. Our reproductive rights are a political issue and we are political now."

Ruth Hermance, 46, of Multnomah, Ore., had the same experience but went the other way. "I used to think ERA [the Equal Rights Amendment] was a detergent," she said at the Eagle Forum meeting in St. Louis. "I stayed home and prayed and thought that was enough to make the country all right." She was even afraid of the League of Women Voters, she said, because they used words like "Senate" and "congressman" that she didn't understand.

Then she learned from the Eagle Forum "that the ERA would take away my rights as a woman." Now she is political in spades: she heads her local chapter, works as a legislative aide and is alternate chairman (not chairperson of chairwoman) of her county Republican Party.

Religion is important to the women on both sides. The NOW gathering resolved solidarity with feminists seeking more rights in the Roman Catholic Church, exhorting the pope: "Sexism is a sin. Repent!"

Many woemn at the NOW convention sported T-shirts that read, "God is coming, and is She pissed!" Church groups are emphasized among the organizations observing NOW's boycott of convention sites in states that have not ratified the ERA.

At the Eagle Forum, speaker after speaker laced their talks with Bible quotes. Several women interviewed at random said that a born-again Christian experience had led them into politics, or that they had first heard of Eagle Forum through church friends.

"I asked God to let me know when it would be right for me to run for office, and He did," said one woman in political strategy session.

At both meetings, the women worried about street violence. NOW has a campaign to "Take Back the Night" and the Forum called for stronger law enforcement. The makers of a chemical self-defense spray concealed in a key chain had booths at both conventions, doing a brisk business.

The two gatherings were almost equally lily-white, middle-class, fashion-conscious and educated. The relative absence of blacks is a source of some embarrassment to both sides, and both sides therefore champion the cause of the poor, each charging that the other's programs will be theiir ruination.

"Phyllis Schlafly is a traitor to her sex," declared NOW founder Betty Friedan, to the cheers of the assembled delegates. "Women's lib literature is a putdown of women," said Schlafly to her audience. "I am convinced they hate homemakers."

It is clear that NOW supporters are overwhelmingly liberal Democrats and that Eagle Forum members are conservative Republicans for the most part. Yet both groups insist their membership is broad-based and only painted as radical by inadequate and sensationalist media coverage.

As proof, both gatherings oddly picked the same July 12 confrontation between Schlafly and Smeal on the Phil Donahue televison talk show. NOW handed out transcripts and Smeal argurd that a random audience of women had showed broad support for her. Schlafly also claimed victory in the meeting and showed a complete videotape of the event at the Eagle Forum convention.

Smeal, 40, and Schlafly, 54, could not be more different in goals. Yet both have viselike control over their organizations. (one wonders whether Stop ERA would evaporate should Schlafly vanish.) Both are upper-middle-class products of middle-sized towns who earned Phi Beta Kappa honors and master's degrees in government from prestigious schools. Both are married with children and spent many years purely as homemakers. Smeal's activism has always centered around NOW, but Schlafly is also a lawyer and has been prominent in Republican politics since the early 1960s.

Their two groups focus now on the Equal Rights Amendment, vowing endless battle to pass it on the one hand or defeat it on the other. NOW's hand-made quilt, raffled off during a plenary session, featured the names of states that have ratified the ERA, with three blank spaces to be filled in -- NOW hopes -- next year. Eagle Forum's quilt, which fell off the wall and nearly covered guest speaker Sen. Paul Laxalt (R-Nev.) at one point, featured -- what else? -- an eagle with stars for the 50 states.

But both groups are looking ahead. "The SALT II treaty is not nearly as complex as Social Security legislation," Schlafly told her chapter leaders. She added that the forum women "are going to take over the White House Conference on Families" next summer. "We'll keep the government from passing laws that interfere with aspects of our lives we don't think they ought to be in."

There were seminars on SALT, Social Security and the family conference at her gathering, along with sessions on how to become a delegate to next year's political conventions and how to be elected to office. NOW offered similar workshops.

"Who Cares About Housewives?" asked a NOW pamplet. It said feminists were largely responsible for changing credit laws, community property laws, Social Security, laws and laws to curb job discrimination against hosewives and all women. "ERA is only the beginning," Smeal told her convention. "We will reach out and form an international movement for women's rights that will never be forgotten."

The two women's organizations remain far apart and receding on sexual questions. NOW's exhibit hall included menstrual flow extraction sponges and lessons on medical self-examination. ("I saw my cervix on Hollywood Boulevard," said one T-shirt.) Eagle Forum speakers repeatedly said sexual matters should be nonpublic and, except for abortion, are not political issues.

If NOW defends homosexual rights as human rights, Eagle Forum still uses lesbian as a swear word. Referring to refuge centers for battered women, one speaker said, "We call them lesbian closets."

Several women agreed at Eagle Forum that the existing socio-sexual system has been more or less kind to them and that they have often conquered adversity through their own personal strength. They think others ought to do the same. They are worried about change they see as more decadent than progressive, and they feel very much on the defensive.

The NOW activists are more angry than worried. They see a world that is changing for the better but too slowly, and they want to help tame a society they view as hostile to the weak. The two sides are convinced there is no common ground between them.

That is too bad. Clearly both groups care deeply about these matters and agree on what the issues are. The Eagle Forum "girls," as they call each other, are just as intelligent, sincere and dedicated as their NOW counterparts, and every bit as certain at a gut level that the opposition is dangerous to everything good and free and right.

The women agree that they will not wait for men to provide the answers: as the poster says, "What if Sir Galahad never arrives?" Politics, they have decided, is the means to the solution, and they are all determined to move what once were only women's issues to the front pages of politics in the 1980s.