President Trump has no evidence for his incendiary claim that Barack Obama ordered wiretaps on Trump Tower, and denials have come not just from the former president and his director of national intelligence but from Jim Comey - the man Trump has showered with praise and retained as his FBI director.
But Trump has something more powerful to him than any evidence, no matter how compelling: He believes. Firmly.
"The president firmly believes that the Obama administration may have tapped into the phones at Trump Tower," Trump spokeswoman Sarah Huckabee Sanders declared on NBC's Today show Monday morning. But what about all the credible people saying it didn't happen? "I think the president firmly believes that it did."
ABC's George Stephanopoulos tried a more direct question on Good Morning America on Monday: "Does President Trump accept the FBI director's denial?"
"You know, I don't think he does," Huckabee Sanders said. "I think he firmly believes that this is a story line that has been reported pretty widely."
The reports mostly say that Trump had made a groundless claim, but never mind that. The White House defense isn't that what Trump said was true. The defense is that "I think he firmly believes" it.
The Trump White House is the ultimate faith-based initiative - and The Donald is the deity. Things aren't true because they can be proven via the scientific method or any other. They are true because Trump believes them to be true.
His advisers' contacts with the Russians? He doesn't believe it: "I saw one story recently where they said nine people have confirmed. There are no nine people. I don't believe there was one or two people."
His fabricated claim that 3 million to 5 million people voted illegally, causing him to lose the popular vote? "It was a comment that he made on a long-standing belief," White House press secretary Sean Spicer explained. An official White House statement called this "a belief he maintains."
He maintains beliefs - herbs in a garden.
Among those attempting to bestow the divine power on Trump to declare absolute truths is Ann Coulter, who last year published the book In Trump We Trust. She tweeted after a meandering media appearance by Trump: "Trump is already head of state. After that press conference, in my eyes, he's now head of church."
Trump, in this position as head prelate, directs us to "believe" any number of things: that manufacturers are returning to the United States, there will be a massive military expansion, that he "inherited a mess" from Obama, and that his Supreme Court nominee is a "great writer."
Trump asked listeners to "believe me" seven times in a single speech last month, saying, "I will never, ever disappoint you. Believe me."
The Yemen raid was a success because "the president believes" it.
"We are not going to let the fake news tell us what to do, how to live, or what to believe," Trump told supporters at a rally last month.
When Trump expressed his belief that news organizations weren't reporting on terrorist attacks, Spicer attempted to document this falsehood with a list of 78 terrorist attacks, most of which had been widely covered.
When Trump expressed his belief that 1.5 million people came to his inauguration, he leaned on the National Park Service to find evidence to support the falsehood and dispatched Spicer to furnish what another Trump aide, Kellyanne Conway, called "alternative facts."
It's not clear, as I've written, whether Trump knows the difference between fact and fiction as he makes up statistics about crime and jobs, alleges he never feuded with the intelligence community, and claims there was bright sunshine during his rainy inaugural address. Survivors of the Bowling Green Massacre know some Trump aides have the same problem.
But look closely, and you can sometimes see Trump aides squirm when called upon to defend his beliefs.
"You said the president believes that there was voter fraud," Spicer was asked at one news briefing. "I wonder if you believe that?"
Spicer explained that saying so wasn't "my job" and that Trump "believes what he believes based on the information that he's provided."
That was quite similar to Huckabee Sanders saying on Monday that "the president firmly believes" that Obama wiretapped Trump - without saying she believed it.
Likewise, Huckabee Sanders, pressed by ABC's Martha Raddatz on Sunday about Trump's wiretap claims, attempted to demur. "I will let the president speak for himself," she said.
"You're his spokesperson," Raddatz reminded her.
And that could test anybody's faith.