Donald Trump's disturbing past in a cult-like church may explain his current delusional nature.

According to Steven Hassan, a former member of a cult known as "the Moonies," Trump's childhood pastor in New York City could have influenced the candidate's infamous ego.

"The other night before the debate [on Sunday], I was watching 'Frontline' with my wife, and they were doing a historical background on Hillary and him," Hassan, who now counsels cult survivors, told Revelist. "What I didn’t know about him, which I think is very relevant, is that he grew up in a church in New York city, where Norman Peale was the pastor—the guy who wrote 'The Power of Positive Thinking.'"

Peale instructed readers that if they wished for something they wanted, they would receive it — but only if they ignored all negative thoughts.

Trump's parents were fervent believers in "The Power of Positive Thinking" and it quickly became a pillar of the family's faith. They started attending Peale's sermons at the Marble Collegiate Church Trump in Manhattan every Sunday.

At the Iowa Family Leadership summit in July, Trump fondly remembered his former pastor.

“I still remember [Peale’s] sermons,” he said, according to Politico. “You could listen to him all day long. And when you left the church, you were disappointed it was over. He was the greatest guy.”

Norman Vincent Peale

Peale's book sold 5 million copies, making it one of the bestselling religious books of all-time. 

But not everyone shared such warm feelings for the man known as "God's salesman."

Many of Peale's critics — past and present — say there was something insidious lurking beneath the preacher's optimistic veneer.

"'The Power of Positive Thinking' is a very problematic ideology, because it’s got features of a cult," Hassan told Revelist. "There’s a belief that there will be some magical thing will happen if you just believe something 100% and you ignore all the doubts and all questions."

"It’s been popularized again for the 50th time by something called 'The Law of Positive Attraction,' but it’s the same teaching of Peale — that if you just believe something 100%, god will deliver it to you."

Unfortunately, positive thinking elicited a not-so-positive result.

In several of his books, psychologist Albert Ellis describes how he treated several of Peale's followers, who suffered mental and emotional breakdowns as a result of his teachings. He said these patients exhibited symptoms characteristic of borderline personality disorder.

"In the long run [Peale's teachings] lead to failure and disillusionment, and not only boomerang back against people, but often prejudice them against effective therapy," Ellis wrote in "Overcoming Resistance: A Rational Emotive Behavior Therapy Integrated Approach."

Hassan speculates that Peale's demagoguery rubbed off on Trump.

"He's a narcissist psychopath who has no empathy, and puts everyone else down and uses fear and guilt to manipulate people into wanting follow him," he told Revelist.

"[Trump] keeps saying, 'Trust me, I know what I'm doing. Trust me.' But he has no plans, no clue as to what he's doing. So there's lots of 'magical thinking.'"

This "magical thinking" is a way cult-like leaders (and Peale...and Trump), persuade followers to blindly trust them, Hassan explained.

"When you look at Trump's behavior, and how crazy he is for even thinking he could run a country...that nobody's going to see what he's really about, it's like he's doing thought-stopping and emotion-stopping for anything that's negative about him," he said.

Thought and emotion stopping is commonly employed by cult leaders to keep their followers obedient.

In Trump's case, one could argue that his repeated attempts to block negative press — and his incessant lying — are all attempts to dismiss any bad thoughts or emotions about him.

After all, how will anyone believe he'll "make America great again" if they realize he's not great at all?

Though it's unclear if Trump still follows Peale's teachings, who taught his followers that self-reflection was a sin, it's not hard to make the connection.

Sure, the candidate's inflated ego is repugnant — but it's also gained him millions of fans. Trump's unwavering belief in himself is scarily similar to that of a cult leader — which is even more terrifying when you consider how much power he wields.

"It's like he's continually programming himself that if he believes he'll be president, he'll be president," Hassan said.

Revelist has reached out to Donald Trump's campaign for comment.

Editor's note: This post's headline has been updated to clarify that Trump's childhood church was "cult-like."