The Rev. Ralph David Abernathy says he "went up into the 'upper room' to talk to my Jesus" when former Rep. Andrew Young (D-Ga.) gave up his Fifth Congressional District seat to become the first black U.S. ambassador to the United Nations.

Abernathy said the conversation ended with divine instructions for him to take Young's place in Congress.

"And now," said Yancey Martin, Abernathy's campaign manager, "I'm not going to let him go up into the 'upper room' no more. I mean, hell, the Lord might change his mind."

There are a number of people here in the crowded race for Young's vacated seat who hope Abernathy will make a second visit to the "upper room" before the March 15 special election. It would make matters easier for everyone, especially for John Lewis, his major black opponent.

Then, too, an Abernathy withdrawal - or a Lewis withdrawal, depending on whom you speak to - would make it easier for a black to retain Young's vacated seat, politicians here agree.

But Abernathy and Lewis - two natonally known civil rights leaders who are personal friends and who were close associates of the late Rev. Martin Luther King Jr. - each plan to plunk down a $1,338 filing fee on Feb. 28, the filing date for the special election.

So do Wyche Fowler, white the well-known liberal Atlanta City Council president; and state Sen. Paul Coverdell, a white moderate-liberal who, so far, is the lone Republican in the race.

And there are a host of others who say they intend to pay the filing fee. Among them are former state Democratic Party Chairwoman Marge Thurman, white; state Rep. J. E. (Billy) McKinney, a popular black Democratic legislator, and the Rev. Clennon King, the black south Georgia preacher who failed in his efforts to become a member of President Carter's Baptist church in Plains, Ga.

All of this has helped to create a strange, free-swinging unpredictable race in which the major candidates - at this point - appear to be Fowler, Abernathy, Lewis and Coverdell.

More than 50 per cent of the vote is needed to win the March 15 race. If no one receive that percentage, there will be a runoff between the two top candidates.

At stake is the representation of sprawling congressional district that encompasses poor, largely black innercity neighborhoods; affluent, predominantly black neighborhoods; affluent integrated and predominantly white neighborhoods, a rural white area, and other urban neighborhoods occupied by middle-to-low-incoem blacks and whites.

Sixty per cent of the district's voters are white, 40 per cent are black and no one seems to know what percentage of the voters are Republicans, Democrats, or independents. In fact, the special election called by Georgia Gov. George Busbee is a free-for-all affair that will not be preceded by party primaries.

Though there are at least the four major contenders for the Fifth District seat, the major focus at this time is on the battle between the two black candidates. It is a curious contest in which the winner - if there is one - is expected to present a formidable challenge to his white opponet.

Both of the blacks, Lewis and Abernathy, have close ties to Ambassador Young, who has chosen not to interfere in the race.

But Lewis has received endorsements from Young's wife, Jean, and the influential Rev. Martin Luther King Sr., father of the slain civil rights leader. Ironically, both Lewis and Abernathy are playing down those endorsements.

Lewis is quietly afraid that a too close identity with Atlanta's black establishment will cost him valuable black rank-and-file voters, who are not above showing their antipathy to the city's black elite. And Abernathy's supporters contend the endorsements have limited value because of Anernathy's appeal to the city's black ministers and black low-income voters.

"There are more poor blacks in Atlanta than there are rich blacks, and the poor blacks will support Abernathy," said Martin, his campaign manager. "Besides that, Abernathy has a ters. Many of them are not familiar with Lewis," Martin contended.

Indeed, Abernathy has been working his "natural constituency" for funds - he believes he needs about $150,000 to make the race - and votes.

In a fund-raising letter sent to 2,000 black ministers nationwise, for example, Abernathy said: "I write you this personal letter because I want to be elected . . . and since you are my friend, I need your help . . . You will recall that I was pastoring in Montgomery Alabama when the late Martin Luther King Jr. came there; and shortly thereafter he and I jointly launched" the Southern Christian Leadership Conference's freedom movement.

Abernathy emphasizes a similar theme in campaigning in the predominantly black neighborhoods in the southern portion of the Fifth District. It appears to go over well there, but Lewis and his backers are betting that it won't play on the predominantly white northside, where any black candidate must garner at least 20 per cent of the white vote to win a congressional race.

Lewis, meanwhile, employs the "Andy Young strategy." He spends at least two-thirds of his time campaigning in * Altanta's black districts and the other one-third pounding the streets and handing out brochures in the northcentral, largely white area where Young picked up much of the white backing that helped to keep him in office since 1972.

"I'm not going to wrap myself in the garments of Anday Young, who is a friend of mine, or in the garments of President Carter, who I know, or in King," Lewis said, speaking of his those of our beloved Martin Luther campaign strategy.

"I don't have to do that. I can and I'm going to run on my record," said the 36-year-old Lewis.

However, Lewis' phenomenal record in registering blacks to vote may cost him white votes. For example, during a recent campaign tour in a shopping center on Atlanta's northside, one white woman told a Lewis campaign aide she wouldn't vote for his candidate "because he's the one who registered all those niggers."

That is the kind of attitude that both Fowler and Coverdell say they hope to discourage should they find themselves in a runoff with one of the black candidates.

"I don't believe that any aspect of the campaign will set off that kind of reaction," said Republican Coverdell, who enjoys substantial support from Atlanta's predominantly white and affluent northside community.

Coverdell, a 36-year-old businessman, said he intends to take maximum advantage of his "base constituency" - northside whites and Republicans - to win enough votes to put him into the primary.

In the runoff, he said, he would "explode out" - campaigning all over the district, including the black inner city, to win the election. He said he doesn't think he'll have any problems winning black votes.

"I'm not the kind of candidate that you're going to have people running out to vote against," he said. "My contention is that I will get a very substantial portion of the inner-city vote because I understand the inner city, and I'm not a divisite candidate."

For his part, Fowler said he is going to lean heavily on his city council record and his two years of service - 1965 and 1966 - as an aide to foremr Rep. Charles Weltner to get votes.

Fowler, 36, said he expects to be in a runoff against Lewis. In any case, he said, he expects to be in the runoff and to win Young's seat.

"My constituency is everywhere in the district," he said, apparently ignoring the fact that he has upset some blacks by criticizing Maynard Jackson, Atlanta's black mayor.

"I have drawn substantial support from all corners every time I've run. I've never won a race where I didn't draw at least 20 per cent of the black vote," he said.

Fowler said he doesn't make the assumption "that all of the black votes will go to a black and all of the white votes will go to a white." If that were the case, he said he wouldn't run.

"That kind of a victory would be meaningless," he said. "The person who would get that kind of a win wouldn't have the authority to govern a district as diverse as this."