Every year, a few dozen folks from Willow Creek Community Church make a pilgrimage to 121 Kellogg Place in Wheaton, Illinois—the home of Gilbert Bilezikian and his wife, Maria. The pilgrims pass a sun porch where Bilezikian, the theologian behind Willow Creek, spends most of his time in the summer and fall.

"We built that porch a few years ago, right where Bill Hybels drove his motorcycle the day he came to see me in 1975," Bilezikian says of his former student, who would become the church's senior pastor.

The Willow Creek pilgrims make their way to the backyard, past Maria's elaborate flower garden and the tomato and cucumber plants her husband tends ("I am better known for my salads than for any theological work I've ever done," he notes, only half in jest), to the spot where Willow Creek was born.

"Right here," says Bilezikian, standing in the middle of his lawn. There Hybels, then no more famous than any other recent college grad, roared up on his bike and said, "Dr. B., you and I are going to start a church."

Armenian surname notwithstanding, Bilezikian is a Francophone who occasionally lapses into French in the middle of a conversation. Born and raised in Paris, he has spent most of his adult life in the United States and was a longtime faculty member at Wheaton College.

Bilezikian's influence at the huge seeker-sensitive church cannot be overestimated. "There would be no Willow Creek without Gilbert Bilezikian," Hybels says.

Hybels was a student at Trinity Evangelical Divinity School in Deerfield, Illinois, during Bilezikian's two-year teaching stint there. At that time Hybels learned the most important word in Bilezikian's vocabulary: community.

That word was later on his tongue as Hybels explained to ...