WASHINGTON — Danny Leydorf's world was about to be turned upside down, and he couldn't wait.

The extroverted teenager had shined at the mostly evangelical Annapolis Area Christian School in Maryland, but now he wanted to test his faith in a more diverse world. With hopes of becoming a lawyer or politician, he badly wanted to understand people who didn't think like him.

"I feel like I exist to be interacting," the lanky, towheaded 19-year-old said eagerly shortly after his graduation.

So he'd deliberately picked a large, secular college: the University of Maryland. But the week before he was to leave, the wider world dealt him a blow.

"I hate evangelical Christians," read the Facebook.com profile of his roommate-to-be, who had seemed so perfect on the phone and who, like Leydorf, loved politics and "The Simpsons."

That was just the first of many challenges and unexpected twists Leydorf has faced this school year as he plunged into the mainstream. He's gone from student body president back home to outsider. He struggles with when to talk about God and when to keep his mouth shut. He wrestles with how Jesus would define tolerance.

Leydorf is traveling an increasingly common path for graduates of private evangelical schools, institutions that sprung up in the 1970s specifically to shelter students from the broader culture. In years past, these graduates often went on to religious schools or overseas mission work. But today's young evangelicals live in a less tidy world, where Capitol Hill and Wall Street are considered mission fields and evangelical leaders are taking more diverse positions on issues that include global warming and homosexuality.

Leydorf had founded the debate team, played junior varsity soccer and was on the student disciplinary board. But what he really craved was the chance to deconstruct the religious and political beliefs with which he was raised. As a senior, he'd even set aside his own "right-of-center" political leanings and pursued an internship with Sen. Charles Schumer, D-N.Y., "a notorious liberal," Leydorf said.

"I want to sincerely seek the truth," he said in May, "not just what you want to believe."

Educational historians say the evangelical private school movement was one of the fastest-growing segments of the private school world from the 1970s, when the schools began, until recently, when growth flattened.

The Association of Christian Schools International, the largest group of such schools, represents 5,000 U.S. schools, compared with 1,000 when it was founded in 1978. But today such academies are at a crossroads as they become more focused on academic success. Parents increasingly want top-of-the-line teachers and SAT prep courses, meaning higher tuition.

The changes in Christian private schools mirror the debates U.S. evangelicals have had about how to best bear witness to a seemingly godless culture: by changing it? Rejecting it? Incorporating it?

Mary Sue Burgess, who was Leydorf's guidance counselor, said the goal of schools such as hers once was to send graduates on to religious schools or mission work, but things have changed. Ninety-eight percent of Annapolis Area Christian School's graduates go to college, compared with 57 percent in 1986, of which only 20 percent go to Christian schools, nearly half of the number 20 years ago.

"A generation ago, it was assumed that if these kids didn't go to a Christian college, their immortal soul was in danger. Now everyone is more relaxed about it," said Charles Glenn, interim dean of Boston University's School of Education and an expert on private Christian schools.

The result of that is a much broader definition of "mission" among evangelicals. Mission work today can mean being a lawyer or professor, as well as building houses in Guatemala.

"We have gotten more assertive and more fearless as far as looking at the whole world," Burgess said. "We want to train our kids to be contributing citizens and not be afraid, not to be stuck in a bomb shelter."

His first week of college, Leydorf estimated he was different from 90 percent of the other students. One kid in the dorm bragged that he hosted a sex talk show. Another invited Leydorf to a strip club. "I'm definitely out of my comfort zone," Leydorf said nervously then.

The biggest change was the feeling that he was squelching his personality. At home, his friends nicknamed him "The Politician" for his tendency to schmooze confidently. He didn't like this newfound reticence.

He'd also decided to say nothing to his roommate about the Facebook remark. He concluded the roommate was using the term "evangelical" as shorthand for religious-right leaders such as Jerry Falwell whom Leydorf, despite his conservative nature, considers intolerant.

One late August day, he compared his sentiments about Maryland to biting into an apple that's mealy: The apple is still good for you, but doesn't taste so good, he said.

By October, some of The Politician was back. Leydorf had applied for a seat in student government, joined the student InterVarsity Christian Fellowship and was attending any event he could fit into his schedule; one day it was a Muslim student discussion group; the next it was a dialogue between an evangelical student group and a gay student group. He was diving into his new challenge: understanding the secular psyche. For example, what exactly was driving the activism he was seeing among nonreligous people?

"For me, if I didn't believe in God, it seems that the natural conclusion is to live life as selfishly as possible," he said. "If I wasn't religious, I can certainly see living my life quite differently."

He also felt himself opening up a bit on the subject of homosexuality. Even before college he'd wrestled with the idea that God sends people to hell; now he felt even less comfortable in judging people.

"You put more faces to (a subject), and it makes a little bit of difference, and you understand it from their point of view more," he said. "If Jesus was here today, he would hang around with the gay community; these guys are shunned."

He paused.

"To me, that's the definition of tolerance — for us to be able to say to one another's face, 'You're wrong,' and be OK with it."