Richard DeVos, who became a billionaire as a co-founder of Amway, and who later became the owner of the Orlando Magic professional basketball team and a contributor to conservative candidates, died Sept. 6 at his home in Ada, Mich. He was 92.

Amway, a home products sales company, announced Mr. DeVos’s death, saying the cause was complications from an infection. He received a heart transplant in 1997.

Mr. DeVos, who was the father-in-law of Education Secretary Betsy DeVos, co-founded Amway in 1959 with Jay Van Andel, a high school friend from Grand Rapids, Mich.

Working at first in a basement and later at a converted gas station, Mr. DeVos and Van Andel built the privately held Amway into a billion-dollar company by 1980, selling such diverse products as cleaning products, cosmetics, jewelry and kitchen appliances.

“We call our company Amway,” Mr. DeVos said, “because the American way of private ownership and free enterprise is the best way.”

Amway was built on a highly personalized sales style that relied on a vast army of “distributors” or door-to-door salespeople. Before they launched the company, Mr. DeVos and Van Andel spent a decade refining their sales technique while peddling vitamins.

Van Andel was Amway’s longtime chairman, and Mr. DeVos served as president and, in many ways, the company’s public face. At revival-style meetings of his company’s distributors, he often invoked the conservative values that guided his personal and professional life.

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“It’s the foundation of my life,” he told the Grand Rapids Press in 2008. “It’s the foundation of my business. We’re all sinners, but we all have potential for greatness as well.”

Mr. Devos drove a green Rolls-Royce, maintained a fleet of corporate jets and made round-the-world voyages on a huge yacht. At times, he flaunted his wealth to inspire his international army of distributors, which the company said numbered more than 1 million.

“The great performers in Amway are a unique breed of people. Those are the real goers, the tigers of the world,” Mr. DeVos told The Washington Post in 1981. “We recognize their self-worth. We keep telling them we love them for whatever they do.”

People in Amway’s sales force worked on commission, increasing their earnings by recruiting other distributors in a practice known as multilevel marketing. New salespeople were required to buy their wares from established distributors and a portion of each person’s sales trickled upstream through the company’s network.

In the early 1980s, the two Amway founders were listed among the five richest people in America. At the time of Mr. DeVos’s death, Forbes magazine estimated his family’s wealth at $5.5 billion.

Amway’s business practices also came under scrutiny by regulatory authorities. The company and its Canadian subsidiary paid nearly $60 million to resolve fraud charges in Canada in the 1980s. In 2010 — long after Mr. DeVos retired — Amway paid $34 million to settle a long-running class-action fraud suit in California.

Critics often derided Amway as a cultlike company built on a pyramid-style business model.

The company spent little on advertising, relying instead on the promise of six-figure incomes. Corporate gatherings, often presided over by Mr. DeVos, turned into exuberant pep rallies with cheers for top earners.

According to Amway figures from 1985, more than one-third of the company’s goods were sold to members of its own sales team. The Federal Trade Commission investigated Amway and ruled that it was not an illegal pyramid organization, saying that the company’s payments to distributors were based on actual sales, not on the number of people recruited.

The FTC did determine, however, that Amway should be more transparent in its recruiting practices and required the company to list, in its promotional materials, the earnings of its sales force. In 2006, for instance, only two out of every 1,000 Amway distributors earned as much as $47,000 a year.

“This is an extremely contentious, controversial business model,” business consultant and author Robert L. FitzPatrick told the Detroit Free Press in 2006. “If you go to work for Hewlett-Packard, you don’t walk in the door saying, ‘Hey, I wonder if this is a scam?’ But anybody who gets into multilevel marketing will have to deal with that question.”

With the growing success of Amway, Mr. DeVos and Van Andel extended their influence to politics and society. In 1977, they bought the Mutual Broadcasting System radio network. In the 1990s, Amway was among the top corporate donors to Republican candidates and causes.

Mr. DeVos was named finance chairman of the Republican National Committee in 1981, and he helped fund such bedrock conservative organizations as the Heritage Foundation, a Washington-based think tank, the Christian advocacy group Focus on the Family and the Federalist Society, which seeks to instill conservative ideals in the legal profession.

He supported measures to provide taxpayer-funded vouchers to parents who wanted to send their children to private schools. His son Dick DeVos espoused the same principle during an unsuccessful 2006 campaign for Michigan governor. Betsy DeVos, Dick DeVos’s wife, has advocated a similar policy.

In 1987, Mr. DeVos was named to the White House AIDS Commission by President Ronald Reagan, but he earned the enmity of gay rights groups through his public comments and his steady opposition to same-sex marriage. He contributed to statewide efforts throughout the country to ban same-sex marriage.

“They were hanging me in effigy because I wasn’t sympathetic to all of their requests for special treatment,” he said in 2009. “Because, at that time, it was always somebody else’s fault. And I said, ‘You are responsible for your actions, too, you know. Conduct yourself properly,’ which is a pretty solid Christian principle.”

Mr. DeVos’s views sometimes led to boycotts of Amway products and criticism of the Orlando Magic, the NBA team Mr. DeVos and his family have owned since 1991.

Mr. DeVos was born March 4, 1926, in Grand Rapids. His father was an electrical contractor, his mother a homemaker.

He grew up in a community made up largely of the descendants of Dutch immigrants, and he was strongly influenced by the conservative tenets of the Christian Reformed Church.

He briefly attended Calvin College in Grand Rapids and served in the Army Air Forces during World War II. After the war, he and Van Andel, a childhood friend, attempted to sail to South America, but their boat sank near Cuba. They were rescued by a freighter and continued their sojourn by land.

After returning to Michigan, they opened a flying school and a drive-in restaurant, both of which failed, before selling Nutrilite vitamins in 1949. They mastered Nutrilite’s multilevel marketing methods, which they later applied to Amway.

Mr. DeVos stepped down as president of Amway in 1993 in favor of his son Dick DeVos. Another son, Doug DeVos, became Amway president in 2002. The company chairman, Steve Van Andel, is the son of Amway’s other co-founder. The company’s revenue in 2017 totaled $8.6 billion.

Mr. DeVos gave millions of dollars to charity, including to medical, educational and cultural organizations, and was credited with spurring a revitalization of Grand Rapids.

His wife of 64 years, the former Helen Van Wesep, died in 2017. Survivors include four children; two sisters; 16 grandchildren; and eight great-grandchildren.

For all the questions surrounding Amway, Mr. DeVos was revered by many of the company’s employees and salespeople. Each month, he sent dozens of notes of appreciation to Amway workers, signing each of them, “Love ya, Rich.”

“I’ve built my business on complimenting people,” he said. “We don’t do that enough.”