Despite his disappointment with today's political environment, the Rev. Franklin Graham publicly defended Republican presidential candidate Donald Trump after Pope Francis questioned his Christian faith.

On Thursday, the pope, responding to a question aboard the papal plane about Trump's promise to build a U.S.-Mexico border wall, said: "A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian. This is not in the Gospel."

Pope Francis weighed in just hours after he prayed at the Mexico-U.S. border for migrants who died trying to reach the United States.

In turn, Trump immediately responded: "For a religious leader to question a person's faith is disgraceful," he said.

As the feud escalated, a number of religious and political leaders jumped to Trump's defense, including Graham, who took to Facebook to share his thoughts.

"I agree that as Christians we should try to build bridges with everyone that we possibly can, but that doesn't mean that we should compromise our national security," the 64-year-old son of Billy Graham wrote.

He added that Trump isn't the only one who wants to build a wall, as other Republican candidates, including Ted Cruz, Marco Rubio, Dr. Ben Carson, and John Kasich have also called for tighter border security.

"[These candidates] as well as millions of Americans, also want to build a wall-in order to protect America from enemies who want to use the U.S./Mexican border as a way to enter our country and do us harm," Graham continued. "Are they not Christian either? My advice to the Pontiff-reach out and build a bridge to Donald Trump. Who knows where he may be this time next year!"

Graham is not the only religious leader to defend Trump: Liberty University president Jerry Falwell Jr., who is the son of the late televangelist Jerry Falwell, told CNN that "the pope is mistaken ... I do believe Trump is a Christian." He added that "JFK would be rolling over in his grave right now."

Catholic League President Bill Donohue also defended the billionaire businessman and accused the media of twisting Pope Francis' words: "The pope was set up by the reporter," he said. "He's been lied to about what Trump has said."

In a statement released Thursday, Trump stated he is a "proud" Christian and accused the Mexican government of using the pontiff for its own purposes.

"The pope only heard one side of the story -- he didn't see the crime, the drug trafficking and the negative economic impact the current policies have on the United States. He doesn't see how Mexican leadership is outsmarting President Obama and our leadership in every aspect of negotiation," he said. "...They are using the pope as a pawn and they should be ashamed of themselves for doing so, especially when so many lives are involved and when illegal immigration is so rampant."

Trump also said that "if and when the Vatican is attacked by ISIS ... I can promise you that the Pope would have only wished and prayed that Donald Trump would have been president because this would not have happened."