By yesterday afternoon Washington scientologists had cleared away the residue of Friday's FBI raid, and the wide brick building at 2125 S Street NW was bustling with its usual weekend crowd - parishioners and communicators, clears and preclears, visitors and auditors.

There were angry words for the FBI, which had conducted joint raids on Church of Scientology offices here and in Los Angeles to recover masses of documents that the government alleges were stolen by scientology spies. While federal officials exulted over the operation - "a jackpot," one said yesterday, "extraordinarily successful" - the scientologists were sweeping away the residue from the buzz saws they claim agents used to break in.

The church has been monitored for years by the federal government, both to investigate allegations that it practices "mind control" on its converts, and to determine whether the group is a bona fide religion qualifying for tax-exempt status. Federal officials maintain that church members have stolen thousands of files containing information on scientologists, while Freedom of Information Act suits to release the information are pending. According to government affidanits, it was those files that FBI agents sought during the raids Friday.

"The lack of manners and breeding of these people," a young woman, at the Scientology officials here, fumed yesterday in reference to the FBI agents involved in the raid. "If you have a search warrant, be gracious enough to wait until people come to work in the morning."

But the business of the day, as on most Saturdays at the Founding Church of Scientology, had nothing to do with the FBI. Inside the carpeted rooms of the three-story Dupont Circle area building, scientologists of varying loyalties - from the mildly curious to the fully committed - were Going Up the Bridge.

That is how scientologists speak of their quest for spiritual freedom. Going Up the Bridge. "It sure is a neat way to go up the bridge," says a handwritten "success story" tacked to a bulletin board on the second-story landing. "A nice return flow." There are other reports from delighted scientologists tacked up nearby: "Life repair really opened my eyes to what these simple processes can do." "I've had my knowingness of correct tech validated several times since starting this course."

To the lay person it is a baffling world of codes and charts and tangled terminology. Missed Withhold of Nothing, Minus Freedom, Keyed-Out Clear, Dynamic Straightwire, Routine 3-D Criss Cross - all these are entries in the Church of Scientology's dictionary, which is used by students studying the teachings of L. Ron Hubbard, Scientology's founder.

But to the college students, the lawyers, the musicians and the athletes who have joined the church, the language is simply code for a system they say helps them achieve spiritual peace.They read Hubbard's numerous books, they follow scientology courses in communication and study, and they use a small machine called an E-meter to recall their own pasts and observe, through the fluctuations of the E-meters needle, the memories that have troubled them to cloud the present.

"There are about six major steps," explained Greg Layton, an architecture graduate of Catholic University who joined the Church of Scientology three years ago now works there full time.Each step, Layton said, represents the confrontation and subsequent stripping away of the negative memories that make up what scientoligists call the "reactive mind." When the last step has been completed, Layton said, a scientologist has reached the peaceful thoroughly trouble-free state the church calls "clear."

"I'm one step away," Layton said. "I hope to achieve it this year."

Layton still remembers reaching the first step. He sat with an E-meter, he remembers, and the counselor scientologists called an auditor. He spoke to the auditor, exploring his own memories a little. And he realized, he said, "that I was not this body right here - this arm and leg is not me - I am a spiritual being . . . My auditor said, 'Very good, thank you, and that's the end of the first session.'"

From there, Layton said, he moved deeper into his own past and then into memories of previous lives.He was a World War II pilot, he said, on the American side. He was an 18th century Washington resident - a doctor, he thinks. He was a 13th century Christian monk. "I've had lots of auditing, so I've had a lot of experiences that have come up in my past lives," Layton said.

As a staff member, Layton received this counseling in exchange for his services.

Members who do not perform services for the church referred to as "public parishioners," pay what the church calls a "required donation." Some samples of these charges were posted in one of the rooms of the Dupont Circle building.

"Word Clearing," the sign said. "38-80-hr." "Cramming - $15.50-day." "Review Auditing - $39.90-hr." The money, Layton said, is used to pay for the upkeep of the house (which was bought by the church when it moved from its original building nearby on 19th Street NW), staff workers' stipends, and a 10 per cent tithe he said is sent to the "mother church," in England.

The cost of scientology has been exaggerated, Layton insisted. He said a genuinely interested person can achieve the goals of the church by studying on his own and auditing with someone besides a professional counselor.

It can mount up. Emil Richard Ellison, a former truck driver and musician who sat in the downstairs lounge yesterday, estimated that by the time he completes his Scientology study and counseling he will have spent "something like $30,000." But he said it's worth it. "There's no way I could describe to you what I've gained from Scientology," he said. "peace of mind . . . it all adds up to spiritual freedom."

"I used to be petrified to get up in front of a jury. Now I can explain what I want to and feel good about it," said George Papaheraklis, 23, an architecture student at the University of Maryland at College Park. Juries are panels of architects who judge student work, and Papaheraklis credited Scientology training for his improved confidence before them.

Papaheraklis said he has studied at the Scientology Mission of Washington, 3411 Massachusetts Ave. NW, since it opened a year and a half ago. He has spent almost $800 on three Scientology courses: the basic communications course, $45; the Hubbard Qualified Scientologist (HQS) course, more than $100; and the Dianetics course, $600. He is just completing part of the Dianetics course.

The Scientology training led directly to better grades in college, Papaheraklis said. He said he doubled his credit load and improved his grades from substandard to A's and B's after taking a Scientology course.

Papaheraklis has also taken Scientology auditing (counseling), and he said his auditor (counselor) has used the E-meter successfully to solve his problems. The E-meter "gradually gets you to see what the problem is . . . I go back in time and try to find out the reason why the problem exists. If I look at the problem, it ceases to exist - banishes - and that's all there is to it."