"Everybody sing ee-oo," declaims the clean-cut thirtysomething at the front of the vast auditorium. Ten thousand Californian voices respond. Over a backing of soaring power chords, the soloist launches into an ecstatic, 1980s-style anthem: "If you're alive and you've been redeemed,/Rise and sing, rise and sing."
Pastor Rick Warren, America's most important religious leader since Billy Graham, emerges from the wings, wearing jeans and a short-sleeved shirt, a trimmed CEO beard and a little more weight than his doctor might recommend. When he speaks, his words are as warm as the Orange County sunshine: the homily is a practical one, advising fathers to pay their children more attention. On gigantic television screens, Jesus on the cross tells John to look after His mother when he dies.
This talent for presenting simple biblical lessons for a suburban age is behind The Purpose-Driven Life, Warren's book detailing his 40-day plan for "Christian living in the 21st century", which is on the shelf of almost every evangelical household in the US. It has become one of the bestselling non-fiction hardbacks in American history, turning the pastor into a sort of spiritual Oprah, with trademarked books and podcasts and appearances at Wal-Mart. Warren's face has been on the cover of Time; and he was chosen to offer the prayers at Barack Obama's inauguration.
Warren set up Saddleback Church in 1980, selecting the location - Lake Forest, a suburb of McMansions and shopping malls - for its transient but growing population. That first Easter Sunday, 200 attended; Saddleback has since grown into a sprawling, 120-acre campus with an average weekend attendance of 22,000. Once, the stereotype of evangelicals as Southern, rural and poor might have been true. Now, they are far more likely to be college-educated, upwardly mobile professionals.
Sixty miles south of Los Angeles, Saddle-back is one of the mega-churches (those with at least 2,000 congregants) that make up the stretch between LA and San Diego known as the "southern Californian Bible Belt". In its grounds, information booths carry maps directing visitors to several white marquees that offer different styles of worship; there are burbling crystal fountains and a baptismal pool that looks like it belongs in an upmarket spa. The teenagers' area, meanwhile, is deliberately scuffed-looking. It contains a big wall display on Aids in Africa - the issue over which Warren has had his greatest impact on evangelicals.
Aids has largely either been ignored by American evangelical churches or treated as a punishment from God. Warren's views are closely aligned with those of the conventional religious right in many areas - in 2004, he said that stem-cell research was "non-negotiable" and compared abortion to a "holocaust".
Yet, a year earlier, he had attended a church conference in South Africa with his wife, Kay. She was recovering from cancer and was keen to adopt a big cause. "So we went out to this little village and found this tent church," he has said. "It had 50 adults and 25 kids orphaned by Aids." He has since joined the Bono/Bill Gates philanthropy club, despatching 7,500 volunteers from Saddleback to developing countries. "I'll work with anyone to stop Aids - Christian, Muslim, Jew, atheist," he says. "That really makes the fundamentalists mad."
When I visit his office at Saddleback, David Chrzan, Warren's chief of staff, says that the media are looking to appoint Warren as the fundamentalist-in-chief. "But Rick would say outright that he's not the leader of the religious right. He doesn't want to be," Chrzan says. "The bottom line is that everyone needs a saviour - Republican, Democrat or Tea Partier.
“Over the past two or three decades, the church became so associated with the Republicans. Now, people are saying: 'Hey, we are for the church - we are not just two-issue people interested in homosexuality and abortion.'" In a 2005 survey of evangelical pastors, 51 per cent said that their congregation was predominantly conservative. By 2008, depressed by Bush's unpopularity in his final years, that figure had fallen to 33 per cent.
There is little evidence that evangelicals are any less agitated about abortion, stem-cell research or gay marriage. But since the recession, moral issues have dropped down the priority list. At Saddleback, too much government, not too little, is blamed for California's disastrous financial state. "Government got greedy," a pastor in Ray-Bans and a leather jacket tells me, "and started taxing business too much."
Most members seem to whistle the old tunes of the right even as they display new-found concern for Africa's dispossessed. Like the Tea Partiers, they are as dismissive of many long-serving Republicans as they are of Democrats and echo the call for "fresh blood" in Washington. "If Palin becomes a viable candidate, they might see her as one of their own - an evangelical person who might get to the White House," warns Scott Thumma of the Hartford Institute for Religion Research.
So progressives who predict the defanging of the Christian right should remember that we have been here before. Ten years ago, a former heavy drinker who had found Jesus ran for the presidency, promising a compassionate and consensual brand of evangelical politics.
We all know what happened next.