The onetime atheist teen-ager from Baltimore who stayed home from school rather than listen to teachers pray, came to the U.S. Capitol yesterday to apologize for his role in the 1963 Supreme Court ruling that ended formal prayers in public schools.

"I admit being beguiled. I admit being misled," said William Joseph Murray, son of strident atheist Madalyn Murray O'Hair. "Now, looking back at the damage that was done . . . I can only urge others to help me correct some of the damage."

The conservative congressmen to the left of him clapped. The fundamentalist minisiters to the right of him clapped. Cameras clicked as he stood, smiling, before the large "In God We Trust" sign. At 33, Bill Murray has found God, quit his job, and set about making amends, embraced as a prodigal son by his newfound friends.

And in a country that has made a small industry out of apologies and conversions, watching everyone from Stalin's daughter to Nixon-era government officials renounce their past, there are plenty of people who want to hear him.

In the two weeks since Murray wrote letters to regret to newspapers in Baltimore and Austin Tex. -- where his mother's American Atheist Center is located -- he has received, by his own count, more than 100 congratulatory letters and two book offers.

He has also appeared on NBC's "Tomorrow" show and been besieged with interview requests.

At first, Murray said, he recoiled from the publicity. But by the end of yesterday's press conference, called by Rep. Philip Crane (R-Ill.) to publicize legilsation that would remove the school prayer issue from the federal courts' jurisdiction, Murray seemed to have adjusted to all the attention.

One after another, congressmen, ministers, veterans and Jaycees were lining up to shake his hand, blinking as the flashbulbs popped.

"When you think that he was an instrument used as a boy to help take [prayer] out of the schools," said James Robison, a Fort Worth, Tex., minister, "it's good he can be used as a man to help restore it. A boy, you see, can be used. A man can make his own decisions."

In fact, Murray has become an instant icon for the national movement to reinstitute school prayers. "He give the movement great visibility," said Dr. William Chasey, a lobbyist for Religious Roundtable Issues and Answers, one of 20 organizations pushing the legislation, which is mired in the House Judiciary Committee.

Sitting in his hotel room Monday night, relaxing after the flight from Houston and jotting down thoughts to be used in yesterday morning's remarks, Murray remained deliberately low-key about his new religion and his new role.

He looks a little older than his years; gray runs through his straight brown hair. Above the neat, light-colored suit of a southern businessman -- which, until Friday, he was -- his eyes are constantly moving back and forth.

"I'm not saying God has brought me here for some special mission," said Murray, turning a pack of Marlboros over and over in his hands and reflecting on his life, recently abandoned, as a middle-level manager for a variety of small and large airline companies.

Every single individual who will be here at the press conference will have some purpose," Murray said. "They are not here for my use. I am not here for theirs. We are all here for the use of God.

"Out of 150 people there, you'll find 149 people with stories better than mine."

His conversion, Murray said, was not a matter of an apocalyptic moment of revelation. "My eyes did not turn glassy and I didn't pick up a Bible and run into the streets to convert others." It was a matter, instead, of months of "intellectual tinkering" with the concept of God, of reading books and of a momentary rejection of the notion of God -- a rejection that he said turned his life to chaos.

Late last year, looking back over everything he said has gone wrong with his life since the day in 1964 when he fled Maryland after a family melee with Baltimore police offices, he decided that unbelief helped cause his troubles, while belief made them manageable.

The troubles, which he described in a monotone, included a teen-age marriage that ended before he was 21, a brief Army career that went haywire after security officers questioned him on his mother's political beliefs, a rootless search for a management job where he wouldn't be asked about the woman he calls "Madalyn," and eventually depression and alcoholism.

Most of all, he said, "for the last 20 years I've been trying to escape Madalyn's overpowering shadow of evil."

He enlisted in the Army in 1968, after two years at the University of Hawaii, a year or so running a taxicab company in Hawaii and a year of working at his first airline job as a load and balance agent dealing with plane cargoes for Qantas Airlines.

He wanted to be a helicopter pilot, he said, so he joined the warrant officers' training program. But then came a security check, lots of questions, lots of forms to fill out. "I broke under questioning," he said, went AWOL, returned to an Army hospital where he said he stayed for a month suffering from exhaustion. After that, until his discharge in 1970, he served in the military police. Hawaii was as close as he got to Vietnam.

Then it was back to airline work -- to Texas and Braniff Airlines this time, for a full four years. "I wanted to be an ideal airline manager. Not the son of a kook," he said.

As he moved from one airline to another, a pattern began to evolve, Murray said. At first "the identity has always been: Bill Murray is a fantastic this, a fantastic that, a great manager, a good pilot [he has a private pilot's license].

"Then someone would find out I'm Madalyn's son . . . As soon as the word got out, that was the subject of conversation, not the business at hand. You know, 'Is she a maniac, Bill?'

"Then I'm no longer the good executive or the fine business manager or the fabulous pilot or whatever. Then I'm Madalyn's son. Period."

In 1975, Murray said, he decided to eliminate the problem by rejoining his mother and working for her center in Austin. What followed, he says now, were two years of "pure hell."

"I'd forgotten," he said, "what close association with a group that was that revengeful and hate-filled was like.

". . . I'd always been a fairly heavy social drinker. By the time I left Austin I was drinking a quart a day. . . .

"I didn't realize how bad it was until a year and a half after I got out of Austin and started looking at myself locked in the bathroom every night with a bottle of Scotch and a bucket of ice."

Every time he mentions his mother, who is now 60, hate, contempt and perhaps pity move in an out of his tone. His father, for whom he was named, "got away from her as soon as he could" and last appeared in Bill's life at a childhood birthday party -- his eighth or 10th, he says.

She, in turn, has nothing nice to say about him. In an interview with the Baltimore Sun the day Bill's letter appeared, O'Hair -- who spent years as a psychiatric social worker -- said, "This is a way of getting back at mother."

Since then, she has stopped talking to the press. The American Atheist Center merely issues the following statement in her name:

"We note in the news that William Murray is going to retire early and live off religious money. We are happy when any atheist gets some of that Christian scam money. We anticipate that he will tithe to the American Atheist Center since the money to him comes from his attack on us. The AAC is not obligated to discuss William Murray's problems."

Mother and son have not talked in three years. Murray, who married again three years ago, said, "she's never seen my younger daughter," Jade, 2. His daughter by his teen-age marriage, 15-year-old Robin, lives with O'Hair.

Of the days in Baltimore when the suit was being fought, the days when street fights were a normal occurence for Murray and hospitals a second home, he has only bitter words. He was the plaintiff in Murray v. Curlett, but the case was totally of his mother's making, he says.

At the time, Madalyn Murray told all comers that it was Bill, aged 14, who prompted the lawsuit by coming home from Woodbourne Junior High School and telling her she would be a hypocrite if she sat back and let schools sanction prayer.

"It's beautifully dramatic," Murray says now. "But it just simply isn't true. Instead, he said, his mother heard the prayers when bringing him to see a counselor one day, and asked if it was a daily occurrence. He said yes. "That bascially started the whole thing."

For him, atheism was not a matter of conscience at all. "It was a non-issue with me," he said -- both during his teen-age years and later, when he helped manage the atheist center. It was only after alcoholism and an emotional unraveling that ended in a confrontation with Houston police last July, that he decided to take religion seriously, he said.

The confrontation came after he locked himself in the bathroom "for several days," until his wife called police and he fired a .22-caliber rifle through a door at officers trying to talk him out.

The bullet went harmlessly between two officers. A SWAT team was called in, Murray was arrested and taken to the Harris County jail, charged with attempted murder of a police officer. Last October he pleaded quilty to a reduced charge of aggravated assault and was sentenced to five years probation. r

"I began to see that as long as I tried to do things my way, without God, it wasn't going to work," Murray says now. "I began to see there was, it was like there was a path laid out in front of me and I'd say 'I don't want to do that, that isn't for me,' and I'd wander off into the wilderness. And God would set me back on the path . . .

"Finally God picked me up and slapped me three or four times in the face and said, 'Would you please pay attention and go back to the path again?' So I did."

Murray won't say what religious denomination, if any, he belongs to. "I don't think that's relevant." But when Crane's office called him on Friday to ask him to participate in the press conference, and he found that 20 different groups -- both religious an business -- would be represented, he agreed.

Murray paid for his $151 plane ticket himself -- he points out that it bears his credit card impression. He does concede that one of the participating groups, he won't say which, offered to pay his way. He hasn't decided whether to accept.

Why did he write the letters that began it all two weeks ago? " I don't know. I felt it was something I should do. I came to believe I had been involved in something that had probably done irreparable damage to the moral foundation of the republic. . . .

"I had the feeling that the only thing I could do was apologize."