The big blue and white air tent and the four 18-wheelers tell it all: Christ is the Answer Crusade. Here on the Mall every summer since 1974, it definitely looks like a power play for Jesus funded by big bucks.

But appearances can be deceiving. The home of this highly visible evangelistic ministry is a field just north of Robert F. Kennedy Memorial Stadium. Children run under lines of clothes strung between old tents, campers and buses that look like they have been out of circulation for years.

One day this week, Ralph Maberry, 29, a missionary, spent most of the day trying to fix one of the ministry vehicles, a beat-up Buick.

Although the Mall revival has ended, the crusade will continue to meet at its Northeast campground through the end of the month, and youthful disciples will continue to spread out to teach the Gospel on city streets.

The ministry began in 1968 when Bill Lowery and his wife, Sara, set out from Milwaukee with a small tent, a truck and 50 young recruits from a Christian coffeehouse. By 1974, Lowery said, their recruits numbered more than 250.

They sent a team to Europe that year and dispatched four young men to Washington who were, in Lowery's words, "saved hippies."

These farm boys "found a big pasture," the Washington Monument grounds, Lowery said. They inquired with National Park Service officials, who said it would take an act of Congress to pitch a revival tent "on the most sacred grounds in America."

Undaunted, two of them approached Sen. Hubert H. Humphrey at 17th Street and Pennsylvania Avenue NW. They told Humphrey about the tent and the senator said he would do what he could.

According to Lowery, Humphrey said something like, "If those marijuana smokers can have a smoke-in down there and those anti-Vietnam demonstators can go down there, by God, we can have an old-fashioned tent revival."

Two other crusaders did similar lobbying at National Airport with then-Sen. Charles Percy.

As a result of efforts by Humphrey, Percy and Sen. Harold Hughes of Iowa, Lowery's team received permission to put up their tent.

In addition to the U.S. team, there are 13 other missionary teams with more than 600 missionaries throughout Europe and Central America. Their budget is about $200,000, all from donations, Lowery said.

Living on the road full-time is not easy, especially when your kitchen is a bus and your bed is on wheels and the job is at the mercy of the weather.

"When we get up and pray, 'Give us this day our daily bread,' this is a serious prayer because no one owns anything," Lowery said. "I don't have a bank account; if I die, my wife would have to take up a collection."

Missionaries such as his 50 members in Mexico have a budget of $500 a week, or $10 a person. "That's not high standard even in Mexico," he said.

The Rev. Bill Mattox had a successful ministry at Victory Baptist Church in Peoria, Ill., but now he and his wife, Jane, live in a 25-foot trailer. They are raising their 2-year-old daughter on the road.

"I paid $250 for the trailer and I'm not sure I got a good deal," Mattox said. "But we plan to keep on living there forever."

The crusade has picked up about six recruits since it moved into town. Robert Dase, 42, originally from Boston and now unemployed and homeless, is one of those. Gerald Mayhan, who works in landscaping, may be another. He and his wife, Phyllis, who works at the Department of Labor, "have a vision of going into the streets," he said. "God set me free from 18 years of heroin addiction. You see me today. I am a changed man."