Scrawled in the upper left-hand corner of the letter is an urgent note: "Get this to my partners the fastest way possible." It carries the initials "O.R."

"O.R." is television evangelist Oral Roberts, and what follows is a remarkable 12-page appeal. It is Roberts' latest request for money, and in it he explains to his "prayer partners" that God has told him to ask each of them for $240 to help find a cure for cancer in his modernistic but unfinished medical center, the City of Faith.

Roberts writes, in a letter that went last month to about 1 million members of his following:

"God said to me, 'It is later than you think. When are you and your partners going to obey me? When are you going to do what I've called you and your partners to do in coming against cancer? I am going to bring mighty and greater breakthroughs for the cure of cancer. When are you going to obey . . . . When?' "

Roberts goes on: "I said, 'Lord, what are the partners to do?' Then in that calm voice I have heard so many times, He said: 'Ask each friend and partner for $240 to be given now or to send $20 a month for the next 12 months as a seed against cancer.' "

At another point, Roberts quotes God as telling him, "Tell them this is not Oral Roberts asking, but their Lord. Spectacular things are going to happen that have never before been revealed . . . ."

Through his staff, Roberts declined to be interviewed about the letter.

Almost six years ago, after his daughter and son-in-law had been killed in a plane crash, Roberts went to the desert to contemplate his grief. There, he says, he was filled with a vision from God, who told him to build a huge medical center, a City of Faith consisting of a 60-story clinic, a 30-story, 777-bed hospital and a 20-story research tower.

Today, that glistening City of Faith stands on 80 acres of the futuristic, windswept campus of Oral Roberts University in Tulsa. About $150 million has been spent to construct the three buildings, linked by a multi-story atrium.

Looming in front of the complex is a 60-foot bronze sculpture of healing hands that symbolize the City of Faith philosophy, the blending of medicine and prayer, or, as Dr. James Winslow, the center's chief executive officer, says, "high-class medicine and effective prayer."

The City of Faith has had a stormy history. Roberts' group first applied for a license for the full 777-bed hospital, but other Tulsa hospitals protested that the City of Faith would create an excess of beds and needless duplication of services. After one health regulatory committee had recommended against the plan, Roberts lowered the request to 294 beds.

The Oklahoma Health Planning Commission recommended approval, and the Tulsa Hospital Council sued to block certification. Eventually, the Oklahoma Supreme Court voted unanimously to license the hospital for 294 beds.

During the legal fight, Roberts said he had another vision, which he also shared in a letter to his partners. "I felt an overwhelming holy presence all around me," he wrote. "When I opened my eyes, there He stood . . . some 900 feet tall, looking at me; His eyes . . . . Oh! His eyes. He stood a full 300 feet taller than the 600-foot-tall City of Faith. There I was face to face with Jesus Christ the Son of the Living God."

George Stovall, vice president of the Oral Roberts Evangelistic Association and of Oral Roberts University, was quoted shortly thereafter as saying, "What he saw, he saw. He would be the first to say, if you had been there, you wouldn't have seen it."

Roberts said the message of that vision was that God would see to it that the City of Faith was completed.

The complex officially opened Nov. 1, 1981, and from the outside it appears to be a fully functioning, if unique, medical institution. Each patient has a doctor, a nurse and a prayer partner, but one staff member, conscious of the image that has developed, said it is not "a Bible-banging kind of place."

"We're not substituting prayer for medicine, nor are we substituting medicine for prayer," Winslow said last week from his office on the 57th floor of the clinic tower. "We're trying to put them together."

The complex appears to have the latest in amenities and lacks only people. Only four floors and 103 of the 294 beds are open. Last Thursday, the hospital was serving 90 patients, somewhat more than the normal patient load of 75 to 85 people, according to public relations director Tim Colwell.

Signs on elevators in the 60-story clinic say most of the floors are closed. And the 20-story Research Tower is only a shell where no floor has been completed. The only cancer research under way is a small effort at Oral Roberts University.

Almost a year ago, Roberts held a rare news conference in Tulsa to say his operations were in financial trouble. He said many of his "partners" apparently had concluded that there was no need to donate more money now that the City of Faith was open.

"I am under obligation to God not to borrow money to operate this ministry," Roberts was quoted as saying by one Oklahoma newspaper. "We are not broke today, but at the rate we are going it might not be far away."

He said at the time that he needed $8 million a month for the City of Faith and $2 million a month for his university and that he would launch a major fund-raising drive.

Sometime last summer, according to Winslow and Stovall, Roberts began talking about finishing the research tower. About this time, Roberts' oldest son committed suicide.

"He was thinking of" finishing the center, "and God was stirring him before" the suicide, Stovall said. But the death of Roberts' son "added some impetus to it, in my opinion."

Winslow said Roberts has long believed that his research center would help in finding a cancer cure. "He's always carried that belief, and in the fall he began to say to me on several occasions, 'Down inside, I know that God is going to provide us an opportunity to make a major contribution, a breakthrough, in cancer in the research center.' "

Last fall, Roberts decided to appeal to the partners in his January letter, according to Stovall, who is in charge of the mailings. Roberts tells his followers that this is no ordinary appeal.

"The Lord has never dealt with me in quite this way before," he writes. "He has spoken to me many times. He has given me visions that I could see clearly in my inner vision. But He has never shared with me such an ongoing conversation . . . ."

Roberts writes that he has received new "marching orders" from God, and concludes that 1983 "is the year to launch a major spiritual plus physical war against" cancer.

Roberts writes that he has told God that he is not a cancer researcher. "Each time He has answered, 'I would not have had you and your partners build the 20-story research tower unless I was going to give you a plan that will attack cancer in both a physicial and spiritual way that is different than other cancer research programs in the world today. I did not have you build this tower debt-free in its present stage just to have it stand empty.' "

"If you read the letter," Stovall said in an interview at the City of Faith, "there's no false hope. There's real hope."

Officials at the American Cancer Society and the National Cancer Institute would not comment on the letter.

The $240 is the largest donation Roberts has ever requested of an individual partner. Those who respond will receive 48 cassette tapes of Roberts reading the entire New Testament.

So far, there have been 130,000 to 140,000 responses, Stovall said, with about 80,000 requesting the tapes and indicating that they plan to pledge something to the research center.

"There's nothing unusual about the response," added Stovall, who has been with Roberts for 27 years. "There's nothing unusual about the letter."