REWATCH: President Trump gives the commencement speech at Liberty University.
UPDATE 12:51 p.m.: Delivering his first commencement address, President Donald Trump on Saturday urged graduates of Christian university Liberty U to follow their convictions but to also be willing to stand up to criticism from others who don't have the courage to do what is right.
"Following your convictions means you must be willing to face criticism from those who lack the same courage to do what is right, and they know what is right but they don't have the courage or the guts or the stamina to take it and to do it," Trump said.
The president encouraged grads to persevere and have git.
President Donald Trump has picked Liberty University for his first commencement address as president.
Trump's remarks Saturday on the Lynchburg, Virginia, campus will mark his first extended public appearance since he fired James Comey as FBI director this week.
The president largely has stayed out of public view since Tuesday, when he removed the head of the agency investigating Russia's role in the 2016 election, along with possible ties between Trump's campaign and the Russian government.
In his weekly address to the nation, Trump said he was "delighted to be participating first hand in the excitement" as students and faculty celebrate Liberty's more than 18,000 graduates.
The commander in chief typically addresses graduates of one of the U.S. military service academies, and Trump is scheduled to speak at the Coast Guard Academy in Connecticut on Wednesday.
"To young Americans at both schools, I will be bringing a message of hope and optimism about our nation's bright future," Trump said.
Jerry Falwell Jr., Liberty's president, helped Trump win an overwhelming 80 percent of the white evangelical vote.
Trump has spoken at Liberty University before. He courted Christians there in January 2016 with a speech that drew laughs from some in the audience when referred to one of the Bible's books as "Two Corinthians" instead of the more common "Second Corinthians."
In that speech, Trump promised: "We're going to protect Christianity, and I can say that. I don't have to be politically correct."
Newly elected U.S. presidents often give their first commencement addresses at the University of Notre Dame, the country's best-known Roman Catholic school.
Presidents Barack Obama, Jimmy Carter, Ronald Reagan and George W. Bush did so during their first year in office. But this year, Vice President Mike Pence will speak at Notre Dame's graduation, becoming the first vice president to do so.
--The Associated Press contributed to this report.