Revered by millions who heard his message of God’s healing power, ridiculed by others for tying his own mortality to a fundraising need, Oral Roberts was a towering figure in 20th century American Christianity.

Roberts, who died Tuesday at 91, was largely out of the public’s consciousness in his later years. His most visible legacy predated his death by 45-plus years: his namesake university in Tulsa, Okla., the first Pentecostal university in the world, built by a man who never finished college.

But Roberts also is credited with being at the forefront of taking the Christian message to television, helping make Pentecostal Christianity mainstream before it exploded across the globe, bringing greater acceptance of divine healing and laying the foundation for the oft-criticized “prosperity gospel.”

“He was a quite significant figure,” said retired Harvard University theologian Harvey Cox, who has studied Pentecostalism, the fiery branch of Christianity that Roberts embraced. “He was controversial, he was ridiculed now and then. But he more than survived. He turned out to be quite a big success.”

Roberts was hospitalized after a fall over the weekend. He died Tuesday of complications from pneumonia in Newport Beach, Calif., a spokesman said.

Born a preacher’s kid in Oklahoma poverty, Roberts overcame both a childhood stutter and tuberculosis at a young age. He said an evangelist praying for the sick healed him at a revival meeting when he was 17.

Roberts took to the pulpit himself. The tall, handsome preacher with Cherokee blood and an Okie accent was a spellbinding speaker at tent revivals on the sawdust trail, said Vinson Synan, dean emeritus of Regent University’s School of Divinity, whose father was Roberts’ bishop.

Roberts’ message was one of healing the whole person — body, mind and spirit. The philosophy led many to call Roberts a “faith healer,” a label he rejected with the comment: “God heals — I don’t.”

Before Roberts came on the scene, “the idea of healing within a religious service was left to Christian Scientists or people who went to Lourdes,” Cox said. “Now, it’s fairly common in churches across the board. In his own way, he made that happen.”

Synan, who ranks Roberts among the three or four most important Christian leaders of the last half of the 20th century, said Roberts was widely loved for bringing Pentecostals, derided as “holy rollers” for their spirit-filled worship and speaking in tongues, into the mainstream.

Just decades later, more than 1 in 4 Christians in the world today are Pentecostal, said Cox. Roberts “was onto some of this stuff intuitively long before it became as big as it has.”

He also was ahead of the curve with his “Seed-Faith” teachings — that those who give to God will get things in return. That laid the foundation for a current generation of “prosperity gospel” preaching televangelists who cite their own mansions and Bentleys as proof of God’s favor.

While proponents call it a biblically sound message of hope, others say it’s a distortion that makes evangelists rich and preys on the vulnerable.

Roberts also was a pioneer in viewing television as a means to spread the Christian message, along with his better-known contemporary, Billy Graham. By the late 1960s, the one-time tent revivalist had evolved into a soft-spoken television orator who welcomed celebrities onto his prime-time variety shows.

“The only really country thing on it was Oral, and he just preached for a few minutes,” said David Edwin Harrell, a Roberts biographer and retired Auburn University history professor.

The programs also featured people of different races together, which was unusual at the time.

Oral Roberts University was the fulfillment of one of Roberts’ greatest ambitions, founded in 1963 at a time when Pentecostals “were considered to be ignorant hillbillies,” Synan said. The school boasted a world-class faculty, mandatory chapel attendance, body-fat measurements and citations for public displays of affection. Students still sign an honor code pledging not to lie, steal, curse, drink or smoke.

The campus is a landmark, with its spaceship-like steel and glass prayer tower and 60-foot bronze sculpture of praying hands, modeled on Roberts’ own. Alumni include prosperity preacher Kenneth Copeland, Republican U.S. Rep. Michele Bachmann of Minnesota and fallen evangelical leader Ted Haggard.

Roberts’ career also was marked by failures and embarrassments.

He said he felt called to an enormous hospital complex that was to marry prayer and medicine, anchored by a 60-story tower. The project collapsed in the late 1980s and left the school with staggering debt.

Then there was Roberts’ widely ridiculed proclamation that God would “call me home” if he failed to meet a fundraising goal of $8 million.

The school is recovering from a more recent setback — the 2007 resignation of Roberts’ son, Richard, as ORU president after he was accused of using university money on spending sprees and other luxuries.

Grant Wacker, a professor of Christian history at Duke Divinity School, said the “God calling me home” episode is not as significant as some claim.

“For true believers it made sense. For the rest of us, it was like, ‘Well, all right. This is an embarrassment. Let’s move on,’” Wacker said. “I don’t think there’s any question it was an embarrassment for millions of Pentecostals. But overall it is so minor, measured against the magnitude of his accomplishment.”