To the hot, dry land of West Texas came the 100 German-speaking Mennonite families, pilgrims from Mexico and Canada who spent $2.6 million for 6,400 acres here, seeking a place for their own church, for their own school and most important, for their own close community.

"I don't know how to explain it," says Frank Wiebe, 25, Mexican-born and currently a Canadian citizen farming cotton fields here. "We are religious people, and we try to stick together, always in a group. We want to stay and work here and be happy and do our best. I don't know what we would do if we had to leave."

But he has been ordered by the U.S. government to do just that. For Wiebe and the 525 other Mennonites here have been ruled illegal aliens, and many of them are recipients of cold form letters saying they must leave voluntarily or face forcible deportation.

"We don't have anything against them. It's the law of the land," said William J. Chambers, district director in Dallas for the Immigration and Naturalization Service, which last week temporarily halted any further action while the group harvests its crops and presents its case. "Under the law, we have to move them out."

That possibility has stirred a calm but real outrage in this hard-working oil and agricultural community of 7,000. They have rallied round the Mennonite cause. Now they are hoping to help their new neighbors win permanent immigrant status by offering jobs for which there are no American applicants. Still, the Mennonites' future is as uncertain as their past is confusing.

That confusion centers on a dispute over what the families were told about citizenship before they sold all their belongings, moved to Texas and invested in a new life. It is a dispute that has split many church members from their leader, Bishop Henry Reimer.

"Everything they have been told has proved to be wrong," says Seminole Mayor Bob Clark.

"We were told to just buy some land and be a Mennonite and be a farmer" and citizenship would follow, said Isaak B. Wall, who conducts the German language school of the Old Colony Mennonite Church. "I was told that by Bishop Henry Reimer. I trusted his words. I would like to know whether U.S. people lied to him."

"I told them it would take 'some amount of time' to become citizens," said Reimer, who also said he never told the group that buying land was the only condition for citizenship.

He denies, too, some member's claim that they did not know that 60 per cent of their 6,400 acres lacks water for irrigation.

Bishop Reimer, whose English is hampered by a heavy German accent, disputed assertions by former followers Wall and Wiebe that Reimer has been deposed from the church's leadership. Reimer does acknowledge, however, that he has missed some Sunday services because of "illness."

Wall and Wiebe claim that Reimer, despite strict Mennonite proscriptions against alcohol, has a drinking problem. Reimer denies it.

Meanwhile, Seth Woltz, the real estate broker who handled the sale, says, "Immigration is just a word to me. I'm at a loss to know how people like that can end up in this situation." Woltz, who says he split a $60,000 commission with two other agents, denied having misled the group's leaders, including Reimer, on immigration requirements. "I just knew nothing about what they had to do. We did take them to the library to give them a copy of the Constitution and the Bill of Rights."

Chambers, of the Immigration Service, cites "this possibility that they were led astray" as one of the reasons for the temporary suspension of deportation procedures.

"Somewhere along the line, we didn't get the picture quite clear," said Wiebe. "We were told if we bought land we could get our green cards" - the ones that entitle immigrants to work in the United States.

The crushing news that they are here illegally deeply affected many members of the Old Colony Church. Memmonites have a reputation for honesty, hard work and paying their debts. And now "they're feeling bad about it." Wiebe said. "Not just for themselves but because we are going against the rules and regulations."

These are not the first Mennonites to know hostility and adversity. Since the sect was founded in Switzerland in 1525, groups first wandered Europe and finally Russia in a succession of religious persecutions. In 1874 they arrived in Canada, Nebraska and Kansas from Russia and northern Germany. It is said they brought with them the seeds for hard red winter wheat, now America's most widely grown wheat.

A large Mennonite settlement was also formed in Mexico. Religious hostility and eventually land expropriations sent many of them to Canada, particularly Ontario. Wiebe moved to Ontario seven years ago. Wall 12 years ago.

But in Canada, land was so expensive that many of the farm-oriented Mennonites had to get jobs: worse, they were scattered apart, some living 80 miles or so from fellow church members. So there arose the notion of finding farm land enough so that an entire community could grow with the crops. (Wiebe says there are perhaps another 2,500 Mennonites who would settle here, with thousands more willing to move to other areas in the United States.)

Thus, last year, a delegation headed by Bishop Reimer visited the United States to see land in Oklahoma, Texas and Missouri and agreed to buy the land here.

The church made a down payment of about $250,000, with the rest to be paid over 10 years, according to lawyer John L. Shepherd, who is now assisting the Mennonites.

Virtually all of the 100 families then sold everything, obtained 60 days non-immigrant visitor visas and began arriving here. They bought land from the church, and rented some: they bought modest homes or mobile homes. Their life savings were used as down payments for purchases that put them in debt for land and farm equipment.

Wiebe says he is $27,000 in debt just on his land. He sits in the linoleum-floored living room of his sparse frame house. Outside on low-green plants the readying cotton has spilled its bolls. With harvest two weeks off, Wiebe had feared being deported before he could bring in his cotton and pay his debts.

In the pale blue one-room school-house, where the boys sit on one side and the girls on the other, teacher Isaak Wall - who came here with $7,500 - says he is now $7,000 in debt. Wall is paid by the church, according to members' earnings, to teach the 49 children aged 5 to 13. The handmade desks hold individual writing slates and thick handsome copies of Die Bibel the basic reading text. But those same desks also hold Hang Ten theme books and at least one copy of Truckin' magazine.

"The biggest reason we are here - this is big open land where we could settle down and have our own church, our own school and make a decent living," Wall, who was an auto mechanic in Ontario, tells a visitor.

For now the congregation of Old Colony has two goals - to be able to stay, and to return their church to harmony. Toward staying, they now pin their hopes on the complicated process in which they can be given jobs if American workers are not available.

Such jobs have materialized in the community, some 100 of them in a factory organized by Realtor Woltz and 14 other investors who put up $10,000 each toward a plant for making wind-mills that generate electricity. The venture was set up specifically to aid the Mennonites, without whom there would probably be no work force. Unemployment here is 2.3 per cent.

But even if the U.S. Labor Department approves the hiring, the Mennonites still must win immigrant visas. Some 20,000 visas are available each year to migrants from Mexico, and the visas are alloted by place of birth. So even though many of the Mexican-born Mennonites are Canadian citizens now, they still must compete with the crush of applicants from Mexico. The annual allotment for Mexico was used up by June, while Canadian allotments go begging. The new allotment year, coincidentally and conveniently, starts Oct. 1.

Chambers says the availability of visas is determined by the State Department and there is no way of knowing whether the group will be among the lucky ones. There are other priorities, other applicants.

In a county (Gaines) that recently pumped its billionth barrel of oil and harvests 200,000 bales of cotton a year, the prospect of hardworking, self-supporting people being deported is a supreme puzzle. The day before Wiebe and the others were to have left the country, the morning paper carried front-page pictures of a new group of Vietnamese refugees arriving, to be assisted by the government. CAPTION: Picture 1, On [WORD ILLEGIBLE] desks in one-room Old Colony schoolhouse, Isaak Wall teaches his Texas Mennonite pupils from thick copies of the Bible. Photo by Ken Feil - The Washington Post; Picture 2, Mennonite children gather to play during recess at Old Colony church school.; Picture 3, Frank Wiebe, 25, would lose his new $25,000 tractor and his cotton fields under deportation order.