America is opening its doors to the homeless. In an outpouring of humanitarian assistance to meet a need that relief officials say is unmatched since the Depression, churches, private organizations , and state and local governments are providing free overnight shelters and at least minimal food to thousands of homeless people across the US.
New York, Atlanta, Chicago, San Francisco, and Boston, among other cities, sharply expanded their services to the homeless this winter.
Now Congress and the Reagan administration are jointly planning to step in with stockpiles of government-owned food and with money to run additional shelters, many of which may be located in unused federal buildings across the nation. The administration opposed such federal funding last year. Congress is ''ready to roll'' in approving the administration's proposed package, which may be included in the jobs bill, says the director of a House subcommittee.
The increase in assistance is due to growing ''public recognition of the homeless, and public insistence that the homeless be cared for,'' says Robert M. Hayes, a former Wall Street attorney now working for the National Coalition for the Homeless, based in New York.
The best estimates of the number of homeless range from 500,000 to more than 2 million, and the numbers appear to be growing. But so far only a fraction of the nation's homeless are being helped, according to church and community leaders in various cities. Many are still spending winter nights in unheated, abandoned buildings, cars, tents, and makeshift shelters.
In Atlanta, more than a dozen churches, with virtually no city assistance, are offering shelter to some 500 persons and food to many more. But some homeless people are still being turned away from full shelters. And most of the food programs offer little more than soup and sandwiches.
''That's the only meal a lot of people have today,'' said one homeless man in Atlanta recently, as he walked out of a soup kitchen at a church here.
Little attention is being given to long-term answers to the problem of homelessness, although the need for more low-income housing is getting renewed attention in some areas with high numbers of homeless persons. Some observers are concerned that once the economy recovers, even less attention will be focused on the long-term homeless.
What the majority of the homeless want, and are capable of handling, is a job , say community and church leaders involved with helping them. The stereotype of the homeless as alcoholics and freeloaders just does not hold up to the facts, they say.
Who are the homeless? According to various experts on the topic, including Mr. Hayes and Mitch Snyder of the Community for Creative Non-Violence in Washington, they include:
* Young employable men (and in lesser numbers, women). This appears to be the largest group. It includes many who have never held a job.
* Other employable persons who have been laid off during the recession. These include everyone from geologists, truck drivers, commercial artists, and a wide variety of other skilled or semi-skilled workers, many of whom have exhausted their unemployment benefits.
* Former mental-institution patients. These may compose as many as one-third of the homeless, experts say. Many can work but need help getting homes and finding work, as well as counseling.
* Alcoholics. This is the smallest group among the homeless.
Many of those helping these people are doing so out of a basic religious concern.
''I believe anyone who says they are a Christian has an obligation to be sensitive and reach out to the poor,'' says Betti Knott of the Atlanta St. Vincent de Paul Society, an international organization of Catholic lay persons. ''The gospel message is very explicit.''
Carolyn Johnson, who helps run a permanent residence in Atlanta for 27 people who would otherwise be homeless, says ''it's not a formula, it's faith'' that led her to a lifetime commitment to provide ''hospitality'' to the poor. She exhibits this as she warmly and gently welcomes a tired, elderly woman to the Open Door Community here.
There are a number of major new initiatives to help the homeless.
Gov. Mario M. Cuomo (D) of New York has pledged $50 million in aid. New York City has increased its shelters, partially under the stimulus of a court order, from 2,600 sleeping places in early 1981 to more than 4,500 now. But there has been court and other criticism of the management of some of the public shelters, which house from 150 to more than 800 people. Privately-run shelters now accommodate about 700, says Hayes.
Massachusetts Democratic Gov. Michael S. Dukakis has pledged $1.2 million for programs to relieve the homeless. The city now has shelter space for about 750 persons, says Nancy Kaufman, a Dukakis aide.
San Francisco recently opened shelter space for 1,100 persons, but the number of homeless in the San Francisco Bay area is about 6,000, says Stephen Wise, who heads a local shelter network.
With support of business leaders, the county that includes St. Paul, Minn., has raised $300,000 for aid to the homeless. And despite some business opposition, the city of Phoenix, Ariz., recently leased a city-owned warehouse to a church group that has just opened a shelter for some 300 persons.