The Hallelujah Chorus, resplendent in flowing gray robes, had performed its special selection for the day, drawing hand claps and shouts of "Amen," when the Rev. James E. McCoy positioned himself solidly in the pulpit.

He surveyed the congregation at St. Paul's Baptist Church in Northeast Washington yesterday morning and raised his powerful voice to the business of the day: "Now, I'm going to talk about gambling."

With that, the minister launched into a 20-minute emotional sermon about sin, the devil, redemption, and, above all, politics. It was a scene that was played out at a number of District churches yesterday, as members of the black clergy -- long thought to be a potent political force in Washington -- urged their worshipers to vote against the controversial May 6 referendum on whether the nation's capital should have legalized gambling.

Outspent by their opponents by nearly seven to one and lacking a paid staff or large numbers of volunteers, the antigambling forces are counting heavily on words from the pulpit as a way of getting voter to the polls.

If yesterday's service at St. Paul's, 1611 Brentwood Rd. NE, is an indication, the ministers' words are not having the impact that they had hoped for.

Moments after McCoy ended his sermon, Franklin Ladson, a retired cab driver and a member of the church for 25 years, told a reporter that he intends to vote for legalized gambling.

"They're doing it elsewhere," Ladson said. "I don't see why D.C. should be different from any other state. If you work for your money, you ought to be able to spend it like you want to."

Asked whether the fact that his pastor opposes the measure bothers him, Ladson said, "You watch these churches. They beg for money all the time. This gambling thing will give people a chance to get some."

"The devil can never be accepted for what he seems to be," McCoy said yesterday. "The devil's make-up is to deceive and destroy. You ought to take the time to look at the gloss and see what's underneath. You will find nothing to solve your problems."

mcCoy is president of the predominantly black Baptist Ministers Conference, many of whose members have led the fight against the gambling measure. It would allow a city lottery and betting on dog racing and jai alai.

The ministers embarked on ambitious plans two months ago to raise $300,000 and buy radio and television advertising to combat the referendum, which they say raises moral and social issues. Despite pleas for contributions, a committee formed to oppose the measure has raised only around $12,000, and most of that has been donated by the ministers' churches, according to a leader of the group, the Rev. John D. Bussey of Bethesda Baptist Church.

McCoy's message was filled with thunderous metaphor and allegory, but he made clear what he was talking about and what he expected church members to do come May 6.

"The devil is painting a beautiful picture and not telling you what you need to know," he said. "When I was a young man, I'd play the numbers. I'd dream the number and I'd put it in. If I dreamed it, brothers and sisters, then I knew that was it.

"But in the evening when the number came out, I was one short. One short! That's the way it's going to be, brothers and sisters. Somebody is going to hit it big, but thousands and thousands are not going to hit it at all."

The congregation gave back an "Amen."

"There are a whole lot of potions around that smell good," the minister said. "They are attractive, and the flavor is high. But down underneath, what we see, brothers and sisters, is sin and degradation."

He told a story of taking his grandson to an amusement park. The child saw a man in a pig costume and went for a closer look, but came running back frightened, thinking there was something wrong with a pig that stood on two legs.

"All this stuff happening around us today is a pig in disguise," McCoy said."You'd better stop and look at it before you go up to shake hands with it. You'd better realize that this isn't a pig at all."

Some church members who went downstairs to the church basement for Sunday dinner of chicken, greens, potato salad, candied yams and apple pie said they agreed with McCoy.

Shirley Martin, a retired city worker, said he thought the illegal numbers game is enough gambling for the city. Artibelle Plummer, who teaches Sunday school, said she feared an increase in crime from people stealing to support gambling habits. "I've got a brother who gambles, so I know," she said.

Response at other District churches yesterday seemed equally mixed.

At the New Samaritan Baptist Church at 610 Maryland Ave. NE, several church members indicated that they were against gambling in principle, but didn't want to impose their views on others.

"I think a person should be able to do what he wants," said James Kennedy, a retired city employe. "I won't vote for gambling in the city because I don't want to go against my church, but I think people should have the right to, if they want to."

Ruth Phillips, a New Samaritan member, said, "I'm going to vote against it because I think gambling will bring more crime into the city. My feeling is that gambling just isn't right."

After his services, McCoy said he was disappointed with the response he has gotten to his call for church members to work against the initiative, and admitted pessimism about the outcome.

"If it passes," he said, "it is going to be because church people voted for it."