John McCain, Barack Obama will appear together at Orange County church

The presidential contenders will share the stage, if only for a few minutes, at a forum next month at Saddleback Church in Lake Forest, the first time -- at least so far -- they will appear together before each party's convention this summer, a spokeswoman for pastor Rick Warren said today.

Warren, the pastor of a 20,000-member, four-campus mega-church, called the McCain and Obama campaigns to set up the event, which will be held Aug. 16, said Whitney Kelley, a spokeswoman for the pastor.

Warren, the author of the best-selling book "The Purpose-Driven Life," will interview each candidate for an hour, one after the other. But they will also appear on stage together for a few minutes.

"The beauty of it is for them to be there at the same time, in front of the same people and questioned by the same person," Kelley said.

The topic of the forum will be "compassion and leadership." A recorded phone message at the church said that Warren "will ask questions that don't often come up in political campaigns."

Though Warren could not be reached for comment because he is out of the country, Kelley said he will most likely focus his questions on how each candidate arrives at his decisions, where they go for counsel and how they view issues of faith.

"I don't think you're going to see any gotcha questions, but he's going to ask them to be introspective," Kelley said. "Questions that will require them to be a little more transparent than on the campaign trail."

Warren incited anger from conservatives in 2006 for inviting Obama, a pro-choice Democrat, to speak at an AIDS conference held at the church. Hillary Clinton spoke there in November.

Once the McCain-Obama appearance was arranged, one more thing had to be settled: Who would speak first?

Warren settled that with a coin toss. The victor? Obama.

tony.barboza@latimes.com