Gordon Bradley, the soccer evangelist, was delivering his revival sermon to 53 people at Rockville's Richard Montgomery High School one day last week.

The former Washington Diplomat coach was on a roll. His mission: to convince anybody who would listen to give $10, or whatever he could afford, to a $5 million drive to bring a professional soccer team back to Washington as a publicly owned corporation for the 1982 season.

"We know the support is here. We need soccer in Washington. It's good for you. It's good for the country. It's good for the world," Bradley preached. "I know you love the game; that's why you're here. We have to continue the enjoyment of professional soccer in Washington. Our approach will be clean and honest. We can make it work -- us, here in this room. I know it can work."

Other people, even eternal soccer optimists, are not so sure about Bradley's public ownership plan. The NFL's Green Bay Packers are an example that it can, having been publicly owned since 1922 with a worth now of about $18 million. But two privately owned franchises in the North American Soccer League already have collapsed in Washington in a year. Can Bradley's group -- Washington Soccer Inc., a not-for-profit organization -- succeed?

"Nobody is more capable of pulling this off than Gordon Bradley, but I think this is a Mount Everest," said Andy Dolich, former Diplomat general manager and now the vice president for business operations for the Oakland A's. "My initial reaction is one of immediate optimism. But they'll have to have a tremendous financial base. I question whether people who have day-to-day financial problems of their own can put enough money into the pot."

WSI has asked nearly 100,000 soccer-playing youths and adults in the Washington area to sell 10 support donations of $10 or more. Prizes, including a car, are being offered as incentives. Charter memberships cost $100. WSI is hoping to recruit 30,000 or more donors.

Some private citizens have pledged as much as $1,000. More than $7,000 had been pledged before the drive started last Monday. As of yesterday, WSI had nearly $20,000 in pledges and cash on hand.

Several local businesses have promised to match the private donations, according to WSI organizers. The prevailing thought is that a soccer club run by Washington, for Washington, in Washington can succeed. If the venture fails, the group promises about 90 percent of the money would be returned.

"I don't know if it can work or not," said John Carbray, another former Diplomat general manager who is now with the NASL's San Jose Earthquake. "I talked with Gordon about it two weeks ago. I have to admire him. But there aren't a lot of success stories like this in sports.

"On paper," Carbray continued, "the public corporation idea makes a lot of sense. But it's the kind of thing you answer one way with your heart, then sit down with your business head and think out a second time. Gordon Bradley is certainly the right guy to do this, and he gets my support in his effort. Any time there's a light at the end of the tunnel, you have to get a little excited. It works in Green Bay. I'd hate to go to a board meeting, though."

Bradley, more than anybody, realizes the risks involved in investing in the troubled soccer league. "I wouldn't take $1 million from any one person," he has said. "It would be a bad investment" to commit such a large sum.

The idea of public ownership in sports is not new in Washington. In 1976, local businessman Joe Wheeler started a campaign to bring baseball back to Washington. He planned to solicit $5 million worth of shares by opening day of 1978, but despite much publicity and well-wishing raised about $100,000.

"This seems like a monumental task," Bruce Holstein, commissioner of a youth soccer program in Laurel, said after listening to Bradley's presentation. Holstein's comments typified the reaction of nearly two dozen people interviewed.

"I'm skeptical, but I'm willing to make the effort," Holstein said. "I hope it can work. There are 600 boys and girls in our program, but I would expect only 10 to 15 percent will try seriously to sell these tickets."

There may be other problems with Bradley's plan. NASL sources say the league prefers that prospective owners have a net worth of $20 million. "My answer to that," said Julian Tepper, a Washington attorney and a member of Bradley's group. "is that $5 million in cash is more than equal to $20 million, net worth. With $3 to $5 million, we would be the most stable owners in the league."

WSI's long-range plan is to charge its members $5 or $10 yearly dues, cut ticket prices substantially and put any profit straight into the local youth programs. Each member would have a say in the club's direction. The group says the franchise would make money within five years.

"Washington United" already is the overwhelming favorite for the team's name. "If we have faith, it can be done," Bradley insists.

Steve Danzansky, president of the original Diplomats, has talked at length with Bradley and counseled him on the pitfalls of such a plan. "I am supportive of any attempt--especially a grass-roots movement like this one -- to bring soccer here," Danzansky said. "My whole heart is with it.

"People say that such things are impossible," Danzansky continued. "But I remember a night in 1976 when the Dips were playing at (W.T.) Woodson High School. It was raining cats and dogs, and only 300 people were in the stands. I was standing on the field to introduce someone, soaking wet, and I looked up to ask Him, " 'Why?' "

"In 1980, I introduced both New York senators to a crowd of 53,000 at RFK Stadium for the Dips-Cosmos game. Even the vice president was in the stands. I looked up to Him then, too, and suddenly I realized there had been an answer. The impossible had been done."