By John Blake, CNN

(CNN) - When Wendell Potter first saw them, he froze.

“It felt like touching an electrical fence,” he says. “I remember tearing up and thinking, how could this be real.”

Thousands of them had lined up under a cloudy sky in an open field. Many had camped out the night before. When their turns came, doctors treated them in animal stalls and on gurneys placed on rain-soaked sidewalks.

They were Americans who needed basic medical care. Potter had driven to the Wise County Fairgrounds in Virginia in July 2007 after reading that a group called Remote Area Medical, which flew American doctors to remote Third World villages, was hosting a free outdoor clinic.

Potter, a Cigna health care executive who ate from gold-rimmed silverware in corporate jets, says that morning was his “Road to Damascus” experience.

“It looked like a refugee camp,” Potter says. “It just hit me like a bolt of lightning. What I was doing for a living was making it necessary for people to resort to getting care in animal stalls.”

The U.S. Supreme Court’s decision Thursday on the constitutionality of the Affordable Care Act is a colossal legal and political issue. For Potter, though, the issue became a crisis of faith.

For the last three years, Potter has been one of the most visible supporters of President Barack Obama’s health care legislation. He has testified before Congress, appeared on countless talk shows and written a tell-all book on the health care industry called "Deadly Spin." With his Southern drawl and mild professorial manner, he has been described as a health care industry “Judas” in some media accounts.

Yet none of the media coverage of Potter has explored what drove his conversion - his faith. Potter was raised as a Southern Baptist in Kingsport, Tennessee, where he says his parents instilled in him an appreciation for helping others.

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He says the New Testament is filled with Jesus providing universal health care - he healed the poor and outcast.

“Christians needed to be reminded of what Jesus did,” Potter says. “It was important to him for people to have access to healing care. That’s what he did. A lot of people of faith lose sight of that.”

A health care hit man

Potter says he lost sight of that because the health care issue was an abstraction to him when he worked at Cigna as a public relations executive. Part of his job was to snuff out stories in the media that made the health care industry look bad.

But his visit to that free clinic in Virginia that July morning shook him. In a column that he wrote for the Center for Public Integrity, a nonprofit investigative news organization, where he works as a senior analyst, he wrote:

“Until that day, I had been able to think, talk and write about the U.S. health care system and the uninsured in the abstract, as if real-life human beings were not involved.”

Yet even after that visit to the clinic, Potter says, he still stayed with his Cigna job. He had a son and a daughter, a six-figure salary, bonuses. He felt trapped even as he resumed his job.

“It was always gnawing at me,” he says of the experience at the clinic.

There was another reason he couldn’t leave his job. It was his identity.

“Our egos are tied to our jobs even if the jobs we’re doing are not what we thought we were going to be doing,” he says. “Our jobs, to a certain extent, help define who we are.”

Potter found a new source of identity - his faith. He read the Bible and found particular solace in the New Testament book of Philippians, where the Apostle Paul advises Christians to “cast all their anxiety” on God. He also read “Profiles in Courage” to fortify his resolve.

He finally quit, and eventually became one of the most visible advocates for health care reform.

“I felt that if I were on my death bed and looked back on my life and realized that I had not taken this risk to do the right thing, I would have huge regrets,” he says.

Why churches are silent

Potter now spends some of his time talking to churches. He says an estimated 45,000 Americans die each year because they don’t have insurance that provides them access to the care they need.

“This doesn’t happen in any other developed country in the world, and it should not happen here, the richest nation on the planet,” he says.

When he takes this message to churches, some shut their doors, he says. They don’t want to hear him. Pastors know the debate over health care divides their congregations.

“A lot of pastors are just too afraid to get involved in this and step up and say this is a moral issue,” he says. “They’re afraid of offending their parishioners.”

Some of Potter’s most consistent supporters, though, are former colleagues in the health care industry. "I've had calls and emails from people I used to work with in the industry who thank me quietly," he says.

No matter what the Supreme Court decides, Potter says health care changes are inevitable. The current system of for-profit health insurance companies is not sustainable. He says some Americans dismiss the uninsured, but they don’t realize how close they are to joining them.

He says many of the people who attended the Remote Area Medical clinic were working people. Their jobs simply didn’t provide enough good medical care. While many companies provide health insurance to people with pre-existing conditions such as high blood pressure or high cholesterol, most people with these maladies wouldn’t get coverage if they suddenly lost their job.

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“Most of us are just a layoff from losing it,” he says of health insurance.

Potter can’t guess what the Supreme Court will decide, but he has predicted what the United States will look like if the health care law is struck down.

We’ve already seen that future in a book and movie called “The Hunger Games," he wrote in a recent column.

"The Hunger Games" depicts a future America renamed Panem, where the government is disconnected from the people who struggle every day for basic needs such as medical care while the wealthy have access to modern medicine, he wrote.

“This society-gone-bad scenario of denying basic care to citizens based on their income or social status seems on the big screen not only cruel and unusual but even incomprehensible,” he wrote. “In fact, it’s occurring every day in what is still called the United States.”

Potter didn’t have to see that future on the screen. He’d already seen it in Virginia, where doctors cared for Americans in animal stalls.