Supporters of D.C. Mayor Marion Barry gave him an emotional and somber testimonial on the eve of his trial last night, telling him to be strong in the face of a legal adversity that is likely to decide his political fortune.

With jury selection set to begin today in Barry's perjury and drug trial in U.S. District Court, several hundred of his supporters gathered at Metropolitan Baptist Church in Northwest to hear speakers recall the mayor's 12 years of service as the District's chief executive. Some in the audience were transported to the event in city Recreation Department buses.

"In the days to come, when they throw things on you, shake it off and step up higher," said the Rev. Carlton Veazey, a friend of Barry's since childhood. As Veazey finished his remarks, Barry strode down the center aisle of the church accompanied by his wife, Effi, and his mother, Mattie Cummings. When the mayor took his seat, the crowd began chanting, "Barry! Barry!"

Last night's gathering ended a weekend in which sources reported little progress in negotiations between Barry and prosecutors over a possible plea agreement.

Associates who spoke with the mayor over the weekend described him as upbeat, almost defiant, on the eve of his trial on 14 criminal counts, including three felony counts of lying under oath to a grand jury.

One close friend said that Barry essentially has ruled out the possibility of an agreement with U.S. Attorney Jay B. Stephens on a guilty plea, and has reconciled himself to a long court proceeding.

"We're going to go forward, and we're not going to let ourselves be coerced or dictated to," one associate quoted the mayor as saying.

The friend said Barry was surprised by what he called the inflexibility of Stephens's position during plea negotiations with defense lawyers R. Kenneth Mundy and Robert W. Mance.

Despite the enthusiasm of last night's service, the program of "prayer, peace and praise" for Barry was considerably more subdued than the other revival-style services the mayor has attended since returning to Washington after seven weeks of addiction treatment in Florida and South Carolina.

In a brief address, Barry spoke passionately about the redemptive power of religion, saying he was putting his faith about the future in the hands of God. "I'm not going to try to figure it all out," Barry said. "It's not in my hands."

The church at which the mayor was honored last night was the same one where he and others ushered in 1990 with a New Year's Eve service.

Eighteen days after that service, Barry was arrested in an FBI drug sting operation at the Vista Hotel, an event that overnight transformed the career of Washington's three-term incumbent mayor and the entire calculus of local politics in the nation's capital.

After being charged with possession of crack cocaine, Barry underwent seven weeks of treatment for what he later described as an addiction to alcohol and two prescription drugs, returning to the city in early March with a dramatic appearance that set in motion a nearly nonstop public relations effort designed to keep intact the mayor's considerable political organization.

Although Barry's defiance in the face of adversity is a hallmark of a man whose political roots go back 30 years to the civil rights era in the South, Barry has in recent days shown another, more philosophical side that contemplates life without the trappings of the mayor's office.

For instance, in a series of revealing interviews last week, Barry spoke at length for the first time about how he hopes history will recall his tenure as mayor, an office he has held since 1979. The mayor also has acknowledged, usually in private groups but occasionally to reporters, being nervous and even "scared" about the possible outcome of his trial.

"I've decided the only thing I can do is make my best effort," Barry said on the "One Washington" talk show that is scheduled for broadcast this week. "If my best effort succeeds, fine. If it falls short, that's all I can do."

Barry also reflected about his years as mayor, likening himself to an oak tree with deep roots in Washington's community and saying that "history will write at some point that we did more good than bad."

Barry also discussed his political legacy last week in his first lengthy interview with radio station WAMU-FM (88.5), comparing his achievements to a baseball game.

"It's the box score that counts," Barry said. "I've struck out in some instances, I've hit some singles, hit some doubles, some triples and some home runs.

"When you add the box score up, the box score for the Barry administration . . . would lead one to the conclusion that if I were to run, I deserve the support of the majority of those who would vote in this city," the mayor said.

As his trial approached, Barry began to talk openly -- albeit with his customary confidence -- about a life after politics. In an interview last week with The Washington Post, Barry said his outlook had changed to the point where he could accept not being mayor.

"There are a number of options available to me," Barry told WAMU. "I have a lot of skills, a lot of abilities. You've had to have these kinds of skills and abilities managerially -- tenacity, creativity, vision, know-how, brainpower, intelligence, integrity -- to have been mayor for 12 years of our city.

"I'm not at all worried about what I would do," Barry added. "I make about $90,000 a year as mayor and obviously, if I weren't the mayor, there's no question in my mind that monetarily I could make three or four times that kind of money.

"There are a number of things I could do that would be almost as meaningful as being mayor," he said. "I'm not going to go bury my head in the sand, I'm not going to go out and curse the darkness and I'm not going to end up in a crazy house someplace because I can't do this job."