If Peter Earle were less pushed by his commitment to the poor, or less haunted by the presence of unemployment and gang-war brutality that victimized Latinos in the Humboldt Park neighborhood of this city, he might have paused for a moment of celebration. He is a member of VISTA (Volunteers In Service To America), and this month the program marks its 15th anniversary.

But as Earle walked along a street the other evening, with a raw and freezing wind rubbing against the bleakness of ghetto destitution, he was leaving the celebrating to others. Instead, he spoke of other anniversaries -- that year after year armies of rats keep attacking sleeping children, that 35 killings occurred in one recent six-month period in turf wars between local gangs, and that fuel bills this winter have reached $200 a month -- in dwellings that rent for $180.

Earle, a Mexican-American who graduated from a small college in Ohio, joined VISTA two years ago. He is one of five volunteers who work as community organizers in a neighborhood citizen's group known in Spanish as the "Coalicion Accion Latina."

Nationally, VISTA has 3,400 volunteers in 50 states. They are paid about $79 a week. Measured by inflated dollars, they might almost be working for nothing. But in the other compensation -- in the personal satisfaction of knowing that your work has meaning, that the system hasn't compromised you and that service to others is the only reward worth seeking -- the payments are large.

The work of Peter Earle and the Latino volunteers in Humboldt Park is worthy of attention because it represents a new surge of energy for the program. They are part of the 30 percent of VISTA volunteers who are poor themselves. A 1973 amendment to the 1964 Economic Opportunity Act ruled that citizens on welfare or getting food stamps could join the program without losing their benefits. Even with them, they are still just getting by. But it meant they could help other poor families.

It meant also that VISTA wasn't merely for rich-kid dabblers who studied Saul Alinsky in college and wanted to "experience" poverty. VISTA was always more than that in actual fact, but because it was created by liberals in the early '60s and was based on the best theories of social liberalism it still annoyed the narrow-mind year after year. Richard Nixon cut the funding to a skeletal $8 million and Gerald Ford tried to phase it out altogether.

But VISTA had too many successes and too many supporters to be done in. At the moment, the Carter administration -- thanks to Sam Brown of Action and Margery Tabankin, the program's current director -- is about to increase the funding from $26 million to $38 million.

In Humboldt Park, the poor helping the poor has led to several community victories that no outsiders could ever have won. VISTA volunteers, by helping to organize block clubs, helped in the affirmative action drive to get Chicago postal officials to hire Latino workers. In 1974, only 1 percent of post employes were from the Hispanic community. After a spell of pressure politics from the bloc clubs, mingled with old-fashioned hell-raising from individual citizens, postal officials are now committed to hiring 14 percent Latinos among new employes. With that victory, the VISTAs set about the follow-through work of preparing Latinos for the civil service tests.

"We worked hard at that," said Mary Lou Porrata, a 27-year-old volunteer who has four children. "Community organizing is sometimes just a question of getting local families to realize that they have some power to improve things -- provided they unite."

For their hard work among some of Chicago's poorest and most scorned citizens, all that Porrata, Earle and the other volunteers can say is that despite the persisting high rates of crime and unemployment, helplessness no longer pervades the air in Humboldt Park. That's not much to point to, except that it's about all any VISTAs anywhere in the country -- the 55 percent urban, 40 percent rural and 5 percent suburban -- can hope to achieve. The poor don't want help. They want the freedom to help themselves.

That has been the purpose of the program all along: Involve the poor in the decisions of their own community. Poverty may persist, but at least the decisions to blunt it won't be poor.