Thousands of people showed up at Saddleback Church Sunday to show their support for the Warrens, who lost their youngest son on Friday. Matthew Warren was 27.
Pastor Rick Warren is the best-selling author of "The Purpose Driven Life."
Warren, leader of one of the nation's largest evangelical churches, says his son's suicide last week was the result of years of struggle with depression and a "momentary wave of despair."
In an open letter to his church, later shared with his nearly 1 million Twitter followers, Warren said Matthew Warren, 27, took his own life at his Mission Viejo, Calif., home.
Matthew Warren struggled with mental illness, deep depression and suicidal thoughts throughout his life, Saddleback Valley Community Church said in a statement.
Supervising deputy Dan Aikin of the Orange County Sheriff-Coroner's Department told NBC News that Warren died from an apparent gunshot wound around 10 a.m. Friday. .
Warren wrote that their son, the youngest of their three children, had enjoyed a fun Friday evening with him and his wife, Kay, but Matthew then returned home to take his life in "a momentary wave of despair."
It was a life-long battle lost, despite consultation with top doctors, counseling, medication and floods of prayer. Despite all that, Warren wrote, "this was an illness that was never fully controlled and the emotional pain resulted in his decision to take his life."
"I'll never forget how, many years ago, after another approach had failed to give relief, Matthew said 'Dad, I know I'm going to heaven. Why can't I just die and end this pain?' " Warren recalled.
Even so, Matthew Warren spent his short life reaching out to others, his father said, calling him "an incredibly kind, gentle and compassionate man" with "a brilliant intellect and a gift for sensing who was most in pain or most uncomfortable in a room. He'd then make a beeline to that person to engage and encourage them."
On Sunday, Warren's brother-in-law and frequent co-pastor at Saddleback would take the pulpit.
Rick and Kay founded their church in 1980 with a few people meeting in their condo. It has since expanded to be one of the nation's 10 largest churches, based in Lake Forest, southeast of Los Angeles, with a network of "daughter" churches throughout California.
Among its hundreds of ministries and support groups are those that focus on people who struggle prisoners, addicts and people living with HIV, depression and other illnesses.
But Warren's first claim to worldwide attention came with his 2002 handbook on applying faith to every day. The Purpose Driven Life has sold 30 million copies and inspired waves of church groups to sponsor 40-day study programs to focus on its short, specific chapters. The book begins: "It's not about you."
In 2008, Warren moved onto the national evangelical and political scene when Saddleback hosted a nationally televised "civic forum" for senators and competing presidential candidates John McCain and Barack Obama.
Warren also drew hot criticism for his efforts to promote passage of Proposition 8 banning gay marriage in California that year. Many gay activists who worked for Obama were mystified that the newly elected president invited Warren to the podium at the first inauguration. Plans for a repeat forum in 2012 with Obama and Republican presidential nominee Mitt Romney fell through because, Warren said, the campaign had become too uncivil.
But Warren had already moved out of the political limelight, narrowing his focus to Saddleback's expanding network of churches and to working on projects in Africa with AIDS orphans, a social program inspired by Kay Warren.