Pentecostal, he concluded, will be the major form of 21st century Christianity.

“The sort of religion that is on the rise is the emotive, assertive charismatic religion,” he said. “It’s compelling Catholicism in Latin America to change. There’s a physical surprise when you go to Guatemala and see how vibrant the charismatic and Pentecostal movements are. Same thing for Lagos and Nairobi. I went into that book underestimating the power and vitality of religion.”…

I asked how he as an atheist reacted to his findings.

“I must say I have more respect, I felt more warmth for religion after doing research for the book,” he said, “partly because of the people I came across, such as the Pentecostal pastor in Philadelphia who has done the most amazing work dealing with crack cocaine. It did strike me that religious people have done amazing work to help the poor. But where are the atheists doing exactly same thing?”