(Bloomberg) —A defiant President Donald Trump told the graduating class at Liberty University to stand up to criticism and challenge conventions in his first commencement address since taking office, a message that seemed aimed at his detractors as much as to the students.

“No one has achieved anything significant without a chorus of critics,” Trump told students on Saturday at the evangelical Christian university in Lynchburg, Virginia, founded by the late Rev. Jerry Falwell. “Nothing is easier or more pathetic than being a critic.”

“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 said. “Be totally unafraid to challenge entrenched interests and failed power structures.”

The speech was Trump’s first major public appearance since he fired FBI Director James Comey on May 9. The move came in the midst of a federal investigation into Russian interference in last year’s presidential election, including possible collusion between the foreign government and people connected to Trump’s campaign.

Since then, the fallout from the Comey dismissal has largely drowned out the White House’s other actions, including a deal with China to promote market access for U.S. beef, natural gas and financial services.

Religious Freedom

Trump delivered his speech under cloudy skies in southern Virginia with more than 50,000 in attendance, according to the university’s estimate. “It is packed,” Trump told Liberty’s president Jerry Falwell Jr., who endorsed Trump during the Republican primary and whom Trump has tapped for input on education reform. “I am so happy about that.”

Trump’s told the graduating class that he would support religious freedom in public life. On May 4 he signed an executive order to give churches and religious groups greater leeway to engage in politics without putting their tax-exempt status in jeopardy. He added that “In America, we don’t worship government, we worship God.”

“In my short time in Washington, I have seen first-hand how the system is broken,” Trump said. “A small group of failed voices, who think they know everything, and understand everyone, want to tell everybody else how to live and what to do and how to think.”

“You aren’t going to let other people tell you what you believe, especially when you know that you are right.”

Heading Abroad

Trump singled out a World War II veteran in the audience and made an oblique reference to the current U.S. war on terrorism saying, “things are going along very, very well.”

“You will be hearing a lot about it next week from our generals,” he said.

The speech also comes days before Trump embarks on his first foreign trip in office, with stops in Saudi Arabia, Israel and at the Vatican, the centers of Islam, Judaism and Christianity, as well as Brussels for a NATO meeting and Italy for a Group of Seven summit.

Trump said he expects to make a “fast decision” on a replacement for Comey, potentially before he leaves the country on May 19. The FBI candidates are “well known, highly respected, really talented people” who’ve been “vetted over their lifetime, essentially,” he told reporters on Air Force One en route to Lynchburg.

Evangelical Turnout

Trump also spoke at Liberty, which calls itself the world’s largest Christian university, in January 2016, shortly before the Iowa caucuses. Evangelical Christians rewarded the Republican at the ballot box in November. “Boy did you come out and vote,” Trump said Saturday.

On May 17, Trump will address graduating cadets at the U.S. Coast Guard Academy in New London, Connecticut. Each year, the U.S. president delivers a graduation speech at one of the U.S. military academies. Barack Obama made his final such address in June at the U.S. Air Force Academy.

Foreshadowing the speeches in his weekly radio address on Friday, Trump said “I will be bringing a message of hope and optimism about our nation’s bright future. That is a message that I want to extend to all young Americans today, especially those who are graduating this year and entering the labor force.”