President Trump delivered his first commencement address as president at Liberty University, a Christian school in Lynchburg, Va. (The Washington Post)

In his first commencement address as president, Donald Trump on Saturday drew a parallel between what he faces as a political outsider in Washington and what he said the Christian graduates of Liberty University can expect to encounter in a secular world.

"Be totally unafraid to challenge entrenched interests and failed power structures," Trump said. "Does that sound familiar, by the way?"

"Relish the opportunity to be an outsider," he continued. "Embrace that label. Being an outsider is fine. Embrace the label, because it’s the outsiders who change the world and who make a real and lasting difference. The more that a broken system tells you that you’re wrong, the more certain you should be that you must keep pushing ahead."

Trump's address was short on scripture but cast the president as a defender of the Christian faith — a mantle he assumed throughout the campaign.

"In America, we don’t worship government," Trump declared at one point. "We worship God."

A president who often ad-libs read from a teleprompter Saturday and stayed mostly on script. And he did not mention the big news of the week — his firing of James B. Comey as FBI director.

Jerry Falwell Jr., Liberty University president and evangelical icon, endorsed Trump in January 2016, calling him "a successful executive and entrepreneur, a wonderful father and a man who I believe can lead our country to greatness again."

Falwell's backing boosted Trump's previously sparse evangelical bona fides and was particularly significant because many political observers had assumed that Falwell would support Sen. Ted Cruz (R-Tex.), who had launched his campaign at Liberty 10 months earlier.

Trump's relationship with Liberty's student body has been rocky, however. When the billionaire spoke at the university a week before Falwell extended his endorsement, students laughed when Trump quoted a passage from "Two Corinthians." The clumsy wording seemed to betray a lack of familiarity with what is more commonly referred to as the apostle Paul's "second" letter to the church in Corinth.

In the fall, after The Washington Post published a 2005 video recording on which Trump could be heard boasting about being able to "do anything" to women and get away with it, a student group called Liberty United Against Trump issued a strong rebuke of the candidate and Falwell.

"We are Liberty students who are disappointed with President Falwell's endorsement and are tired of being associated with one of the worst presidential candidates in American history," the group's statement read. It added that Trump "received a pitiful 90 votes from Liberty students in Virginia's primary election, a colossal rejection of his campaign."

Three students authored an opinion piece in The Post, writing that "Trump is the antithesis of our values."

But the president received a warm reception on Saturday from the roughly 50,000 commencement attendees — a record crowd for the university, he proudly announced. Falwell said Trump is the second sitting president to deliver a commencement address at Liberty; George H.W. Bush spoke in 1990.

President Trump delivered his first commencement address as president on May 13 at Liberty University, a Christian school in Lynchburg, Va. (Claritza Jimenez/The Washington Post)

Falwell also said he was honored that Trump picked Liberty for his first commencement speech. Several presidents, including Barack Obama, George W. Bush, Ronald Reagan and Jimmy Carter, have spoken first at the University of Notre Dame. The White House will dispatch Vice President Mike Pence to the Notre Dame commencement next Sunday.

More than 6,100 graduates attended Liberty's ceremony, 68 percent of whom attended classes online and probably had never been to campus before this week. Following a torrential rainstorm Friday night, the sun made an appearance just as the grand procession began. Still, women's heels sunk into wet grass, and some opted for rain boots instead.

Trump received a degree of his own at the ceremony — an honorary doctor of laws degree.

In a lighthearted moment, Trump listed some of the schools that Liberty's football team will face in 2018, when it joins the top tier of collegiate competition. Opponents will include such traditional powers as Auburn, Virginia Tech and Ole Miss.

"Jerry, are you sure you know what you're doing here?" Trump quipped.

Jenna Johnson contributed to this report.