The biggest geek in the senior class is sitting alone in the bustling high school cafeteria. He stares self-consciously at his plate, pushes his food around, counts the minutes until the period is over. Suddenly the captain of the football team is standing above him with a smile. "Hey, come sit with me and the team over there …" the player says.

What sounds like a dream sequence in a nerd's wish-fulfillment movie is no fantasy at the Gilman School in Baltimore, Maryland, where volunteer football coach Joe Ehrmann teaches his Gilman Greyhounds a different brand of leadership: "base your actions on the simple question, 'What can I do for you?'"

"American men most often define themselves by comparative athletic ability, sexual conquests, and economic success," Ehrmann says. "We compare. We compete. That's all we ever do."

Ehrmann was no different. The former college All-American spent 13 years playing professional football and acquiring all the trappings of success. But he wound up with "destination sickness," in his words, which left him empty and unfulfilled. Eventually Ehrmann made a decision of faith, graduated from seminary, and started a successful ministry. But a few years later, he realized he had simply Christianized the world's view of leadership he already knew too well: "buildings, budgets, and body counts."

Eight years ago, along with friend and head coach Biff Poggi, Erhmann began to volunteer as defensive coordinator for the Gilman Greyhounds, where the young charges were taught a new approach to success and leadership: define yourself by your relationships and your pursuit of a greater cause: "What kind of teammate are you? What kind of son are you? What kind of friend are you?" Find a larger purpose for your life, so that in the end you will "know that the world is a better place because you were other-focused."

In the football-saturated culture of the American high school, where athletes are demigods who can do no wrong, Ehrmann's coaching style is novel, to put it mildly. But his emphasis on service and purpose echoes the Apostle Paul, who wrote that although Jesus existed in the form of God "[He] did not regard equality with God a thing to be grasped, but emptied himself, taking the form of a bond-servant, and being made in the likeness of men."

Ehrmann starts by telling his players that his job as coach is to love them. Their job is to love each other. Members stay on the team even if their playing is less than perfect. Seniors always play, and before the season's final game, everyone must write and read his own mock obituary. Ehrmann's teams have remarkable success on the field, but the score, he says, is only "a byproduct of everything else we do—and it's certainly not the way we evaluate ourselves."

Just ask the nerd in the lunchroom.