You had to stand up in the congressional hearing room since, for a change, the subject was one of importance and the seats were long since filled.

Elevated above the common floor was a dais occupied by members of the House of Representatives who were prepared, as usual, to notify the groundlings they had spent their lives (as Rep. Parren J. Mitchell D-Md. pointed out) in bettering the lot of the common and downtrodden man.

The main witness, Mitch Snyder, walked in done up in an Army fatigue jacket of soft mouldy olive green, a turtleneck knit shirt of sandy beige, blue jeans of unknown manufacture -- these are fashion notes; what men of consequence in the capital are wearing.

He told the congressmen, who have just voted themselves a long-overdue pay raise, that they are not cutting the mustard.

The topic on Wednesday was the 2 million homeless Americans who live on the streets or in cars or in tents or God knows where else.

"You can find teachers sleeping under bridges," Snyder said.

"Would it be advantageous to hold hearings in all 435 congressional districts?" Rep. Mitchell inquired.

Snyder said of course it would be helpful, anything would be helpful. But what he was asking (preposterous, of course, since Snyder for some time has been a preposterous citizen of this capital) was for the Congress to open federal buildings for the homeless to sleep in at night and stay warm.

He said there are from 5,000 to 10,000 homeless people in Washington. He suspects the figure is larger. The city government, which does not like thinking about the matter, thinks there are 1,000 to 3,000 homeless here.

However many there are, you can see them on the capital's streets and heat grates if you feel like looking, not that there are many connoisseurs of such landscapes.

Snyder, who operates with an outfit called the Community for Creative Nonviolence, lived four months a while back on a heating grate and did not much enjoy it, but he figured if you're going to sound off about the homeless, you had better know how they really live: the lines they stand in, the resistance they feel to being herded like animals and (from some shelters) dumped out on the street at 5:30 in the morning. Snyder himself moves from the center back on the streets later this month.

Once everybody had admired his smart clothes -- a quite funky iron cross on a chain about his neck -- we settled down to give him a good five-minute audience, but, you know, he was not all that polite.

"I credit him for these hearings," said the chairman, Rep. Henry B. Gonzalez (D-Tex.), "his intense interest in trying to arrange these hearings."

So you would expect, based on the various other congressional hearings you have sat through, that Snyder would be pleased with this praise and would lay it on thick; how marvelous the congressmen are. Instead:

"The president Ronald Reagan has been incredibly adroit creating three-ring circuses. Local officials everywhere are not keen to acknowledge the number of the homeless. But if you yourselves were living on the streets right now, the congressional bills would fly. You would do more than you're doing now.

"I am not talking now about long-range things, but an emergency. I am asking that Congress open its doors to the homeless. There are more homeless now than there were even in the Great Depression. It is a national emergency and I am asking that you face it as such.

"People are waiting for an example, waiting for leadership, and they haven't gotten it."

"This is not a new thing," said Gonzalez. "I don't know of any community that is dealing adequately with the issue."

Snyder was asked later if there had been much response from a letter he sent a few weeks ago to all congressmen requesting government buildings to open for night shelter to the homeless.

"While we were feeding people on Lafayette Square we got word that the president was thinking of taxing unemployment benefits. I guess that's a response of sorts."

"I suggest," Snyder told the congressmen of the Banking Committee's subcommittee on housing, "that you or anyone else who seeks a position of authority, should spend some time on the street . . . And we beg you, then roll up your sleeves and get to work."

The chairman observed that, "We in Congress are somewhat more insulated."

Gonzalez agreed to hold the hearings, a thing some congressmen would not touch with a pole. Who wants to hear about real problems? Surely more congressional hay is made conferring with rich lobbyists.

"The myths are," said Mitchell, "that they don't want to work, that they don't want help."

Snyder, concentrating on not exploding, said, "We must remove the barriers, let those people in, and see who they are. Get closer to them, and the stereotypes fall in a little heap at your feet."

As Snyder has long and consistently said, it's true that many street people had rather live in a cardboard box or die frozen in a doorway than accept the "pigpen" conditions commonly offered them, or suffer the violence of guards at some of those shelters. They may be bums, but they're American and most of them grew up proud, and will die before they accept being treated as pigs. But (Snyder keeps arguing) if anything decent is offered, by any decent people, the street folk will leap to it. They really do not enjoy freezing to death or feeling their stomach gnaw at 6 in the morning, and few of them really have an esthetic taste for lice and vermin, the smell of body waste or the clam of sodden shirts.

Snyder, who is greatly respected by some in the capital, is hated by many others.

"I wouldn't give a dime to keep him alive," said one woman a few days ago when his name came up.

He offended many by telling Holy Trinity Church it ought to spend more on the poor and less on the roof. He decided to fast in protest, and it nearly cost him his life. This was widely regarded as "moral blackmail," which Holy Trinity righteously resisted.

The bad omen for Snyder was that the city in general perceived it need not have been a Roman Catholic church, but could just as easily have been any other. And it needn't have been a church, for that matter, it could have been any institution or almost any individual.

His message, implicit for some years now, is both clear and infuriating:

Get off your a-- and feed the sheep.

A message as unwelcome and unpleasing now as in 30 A.D.

He is not judgmental. He thinks everybody will help, once he faces the fact that people are hungry, people are cold, people are in rags, and that's why his first priority is to ask the Congress itself to open the heated halls of the taxpayers to the ones who sleep cold. Then people will leap to action.

In the interest of sound context and historical objectivity, it should probably be said Snyder knows very little history, and even less of the human heart apart from his own.

His own particular howl, unfortunately, has its own echoes. He is asking what we are doing and few of us relish the question.

There was once a Presbyterian preacher, the tough rugged sort, who said a guy wound up in hell and started hollering at the first blast of the furnace:

"O Lord, I didn't know. I didn't know."

And there was a moment of silence then a great thunder from on high:

"Well, you know now."

I never laid eyes on Snyder till this hearing in the Rayburn Building, but somebody told me he's a Roman Catholic. That would be nice, I should think. He might get turned into a saint some day, once the yap-yap of ecclesiastical lawyers is completed and there's no danger of his touching living men.

I myself feel in a somewhat less enviable position, heaven-wise.

One of the amusing scenes of our literature, though with a bite to it, occurs in Marlowe, whose hero, Faust, faces death. Old Faust lived a conventional life devoted to learning and many commendable things. He made a few little arrangements and bargains along the way to effect the Good Life, as we now call it. Something seems to have gone wrong, however. He says:

"See, see how Christ's blood streams in the firmament. One drop would save my soul. Half a drop."

You feel sorry for old Faust. Reminds us of all our buddies and ourselves. There's a silence, then some thunder and he gets burnt to a cinder. Heh, heh, heh.