NEW YORK — One of America’s leading evangelicals believes a new pastoral letter on mental health by California’s Catholic bishops serves as a “watershed moment, and a new standard for mental health ministries around the world.”

On Wednesday, the California Catholic Conference released “Hope and Healing,” a pastoral letter calling for an end to the stigma around mental illness and greater collaboration between science and medical professionals and people of faith.

RELATED: California bishops call for an end to social stigma around mental illness

According to Pastor Rick Warren, founder and pastor of Saddleback Church in Lake Forest, California, the document will be used “not simply by Catholics and Christians in California, but also by non-believers.”

In an interview with Crux, Warren praised the document as being “very well-written,” noting that it’s “both pastoral and scientific.”

Warren is quoted in the letter calling for greater recognition that mental illness is not the result of a lack of faith in God.

“Your chemistry is not your character,” Warren states, and “your illness is not your identity.”

In recent years, Warren has become one of the nation’s leading Christian voices speaking out against mental illness related stigma and calling for Christians to dedicate more resources to mental health awareness.

In April 2013, his son Matthew committed suicide after ten years of living through a “deep, deep depression.”

Warren recalled his son’s decade long battle with mental illness, saying that at age 17 he asked his parents “Why can’t I just go to Heaven now?”

“He was the most courageous kid I ever knew,” said Warren.

Since his son’s death, Warren and his wife Kay have dedicated much of their time and resources in issuing a clarion call to their fellow Christians not to neglect mental health — and one of his closest collaborators has been Bishop Kevin Vann of Orange, California.

When Vann arrived in Orange in 2012 following his previous appointment as bishop in Forth-Worth, Texas, he and Warren became “quick friends and prayer partners.” Although Warren had attended seminary in Fort Worth, the two did not know one another until Vann began his post in California. Warren attended Vann’s installation and “now we text each other all the time,” Warren told Crux.

“When Matthew died, one of my first calls was to Bishop Vann,” Warren remembers. “He so graciously and tenderly said to me, ‘What can we do about mental illness? How can we partner together?’”

Since then, the two have hosted two gatherings on mental health and the church between Saddleback and the diocese of Orange, and the new pastoral letter is now another fruit of their joint labors.

Their message: “It’s not a sin to be sick.”

“If your liver stops working, and you take a pill, there’s no stigma. If your heart stops working, and you take a pill, there’s no stigma. Why is it that if your brain stops working, and you take a pill, then there’s a stigma?” asks Warren.

Nearly two years ago, the state of California legalized assisted suicide, which along with the Catholic bishops of the state, Warren has opposed for many of the reasons he insists Christians have to care about mental health.

“Jesus said that I’ve come that you might have life, and have it abundantly,” says Warren. “We’re now in a culture that glamorizes death over life, but as Christians, we are affirmers of life not death.”

“People ask me if I’m pro-life,” Warren continued. “I don’t call myself a pro-life Christian.”

“I call myself a whole life Christian.”

“I believe that a little girl not only has a right to be born, but should also get a full education and be protected from abuse. I want to keep her off drugs, and if she gets depressed, I don’t want her to struggle with thoughts of suicide or depression.”

“We care about all of life issues, and whether a person is in their depressed mind, confused mind, or dementia mind, they still matter to God,” he said.

Last fall Pope Francis made headlines when he revealed that he benefited from regular psychoanalysis in the 1970s that helped him “clarify things.”

Warren told Crux that statements from high-profile Christians such as Francis are critical in ridding the stigma that too often surrounds mental illness.

He said it’s for that reason that he and his wife have talked very openly about the benefits they’ve received from marriage counseling over the years and other types of support.

“It’s nonsense to think we’re supposed to make it through life on our own,” said Warren.

“The phrase ‘one another’ is used 58 times in the New Testament of the Bible,” he continued. “We’re told we have to pray for one another, counsel one another, love another, and so on. Everyone needs counsel at some point of life. There’s no shame, there’s no stigma, and there’s no sin in that.”

“We just need to blow off the door and let the light come in,” he said.