Two decades into his tenure running Raytheon Co., Thomas L. Phillips paid a visit to a class of business graduate students at Suffolk University and offered uncommon advice.

Mr. Phillips, who was 94 when he died Wednesday in his Weston home, told the aspiring MBAs that he would never reprimand an employee in front of others “because the dignity of the individual must be preserved.”

To run a good company, he added, trust and integrity are essential.

An unusual figure among the executives who transformed Route 128 into a premier technology corridor, Mr. Phillips was 40 when he became Raytheon’s president in 1964.

“It was under Tom’s vision and leadership that Raytheon grew into a global defense technology leader — a legacy we continue to build upon to this day,” Thomas A. Kennedy, Raytheon’s current chairman and CEO, said in a statement. “Tom was a link to Raytheon’s past and future.”

An electrical engineer by training, Mr. Phillips helped turn Raytheon into a billion-dollar business, then a multibillion-dollar enterprise.

And he did so with what Wall Street analysts called a gentlemanly style. More precisely, Mr. Phillips was a CEO grounded in his Christian faith.

A few years into leading Raytheon, he “attended a Billy Graham crusade in New York City and responded to the call,” Mr. Phillips recalled in an interview posted on a website of Gordon College, on whose Board of Trustees he served for many years.

“I knew it was all different from that point on,” he added. “I walked out into New York City and it was raining slightly and everything was beautiful. It was just an amazing experience.”

Mr. Phillips paired his approach to leadership with a professionalism rooted in Raytheon’s mission. Before arriving at the company, he had graduated from Virginia Polytechnic Institute with a bachelor’s degree and a master’s in electrical engineering.

He joined Raytheon in 1948, the year Charles Francis Adams became the company’s president. Adams later served as board chairman during the early years Mr. Phillips was president.

Rising steadily and quickly, Mr. Phillips became manager of the missile systems department five years after arriving. He was named a vice president in 1960, general manager of the missile and space division early the following year, and executive vice president by the close of 1961. Three years later, he was president. He was named CEO in 1968, became chairman in 1975, and retired in 1991.

While Mr. Phillips was CEO, Raytheon “developed the Patriot missile defense system, navigational computers used on the Apollo lunar missions, the Cobra Dane early warning radar installation, and the Standard Missile franchise,” Kennedy said. “Tom Phillips’s business acumen grew Raytheon’s revenue 18-fold during his tenure.”

Diversification was a hallmark of his leadership. Though Raytheon’s post-World War II reputation and success were closely linked to its missiles, Mr. Phillips and Adams believed the company would need other revenue if military spending tapered off. As a hedge against that possibility, Raytheon acquired companies in the engineering and publishing fields.

US Attorney General Richard Thornburgh (right) joked with Mr. Phillips after the Raytheon chairman and CEO was awarded the annual “New Englander of the Year Award” in Boston. With the two was Bonnie Newman. Associated Press/File 1988

In some ways, the two were an unlikely pair to guide Raytheon’s success. Adams was the great-great-great-grandson of President John Adams. Born to Greek parents, Mr. Phillips had arrived in Boston as an immigrant, via Canada, with an Anglicized name.

In 1985, Adams told the Globe that Mr. Phillips was “a man with a first-class mind and first-class character.”

Among those whose lives Mr. Phillips changed was his friend Charles Colson, who had been special counsel to President Richard M. Nixon and who served a prison term for his role in the Watergate scandal. Inspired by Mr. Phillips’s faith, Colson became an evangelical Christian and founded the Prison Fellowship, a now-international outreach organization for inmates, former prisoners, and their families.

“He led me to Christ,” Colson said of Mr. Phillips in a 1976 interview with The New York Times. “What had happened in his life became a model in my own.”

Amid the Watergate investigation, Colson visited Mr. Phillips in Weston in 1973. Mr. Phillips read aloud to him from the Bible and “Mere Christianity,” by C.S. Lewis, “and out on my driveway, right there, he committed his life to Christ,” Mr. Phillips recalled in the interview for Gordon College.

Though Mr. Phillips was somewhat private about his faith, Colson was more open and recounted that encounter in “Born Again,” a memoir. “As a result of Chuck’s book ‘Born Again,’ I was out of the closet as a Christian for everybody to see at Raytheon,” Mr. Phillips said in the Gordon College interview, “and it worked out just fine.”

The younger of two siblings, Thomas Leonard Phillips was born in Istanbul to Greek parents, Andromache and Leonidas. He was a boy when his father died and moved with his mother and sister first to Athens, then Paris, and eventually to Canada.

Mr. Phillips was told by his mother and sister that he was born in 1924, though Canadian immigration records suggest he was a year older. He always used 1924 as his birth year.

“My father was very stoic and strong,” said his son, Tom of New York City. “He always said he got a lot of breaks along the way.”

According to a family story, Mr. Phillips sold newspapers as a young boy in Canada to help his family’s finances. He didn’t understand why the tips were large and numerous on one particular day until his boss explained that it was Christmas.

When Mr. Phillips was 12, his mother married a widower and they moved to Mission Hill to become a blended family of seven children. Excelling at Boston Latin School, Mr. Phillips started his college studies at Northeastern University, where he played football and basketball.

At a dance, he met Gertrude Van Iderstine, a Wheelock College student, and they married in 1944. Drafted into the military, he left Northeastern and was stationed in Virginia, where he began taking classes at Virginia Tech while still serving in the Army.

After graduate school, Mr. Phillips was about to launch a teaching career when, on the advice of a Boston friend, he inquired about working for Raytheon. He was hired and stayed there his entire career.

To encourage other business leaders to think about ethical questions, Mr. Phillips founded First Tuesday, a group that met for breakfast once a month. Among those who attended over the years were Kenneth Olsen, who cofounded Digital Equipment Corp., and Governor Edward King.

Mr. Phillips also served on many boards, including those for Digital, John Hancock, and Knight Ridder, and he endowed a scholarship fund in his family’s name at Boston Latin.

Despite his many business commitments, “he would say, ‘Put family first’ — that family was ahead of anything professional,” his son said. “And he would repeat that throughout his life”

In addition to his son, Tom, Mr. Phillips leaves three daughters, Patty Fraser of Concord, Bobbie Suratt of Wellesley, and Debbie of Rye, N.Y.; 11 grandchildren; and 12 great-grandchildren.

A funeral service will be held at 2 p.m. Jan. 20 in Trinitarian Congregational Church in Wayland.

Mr. Phillips was so committed to his faith that he carefully considered the potential use of weapons Raytheon manufactured. “If I thought we were providing provocative or offensive arms then I would feel at an impasse as a Christian,” he told the Times in 1976.

Ultimately, he believed defensive weapons were necessary in “an imperfect world,” he told the Globe in 1985.

“We would like it to be a world where armies and weapons were not necessary,” he added, but people are “flawed, I believe. And nations are flawed. We have to provide for a common defense just as a city must protect its citizens with a police force.”