Until last fall, a 25-year-old Seattle man named Andrew was happily committed to Mars Hill Church, one of America’s fastest-growing megachurches with more than 5,000 members. He volunteered weekly for security duty at his branch of the church, joined a Bible study group, and had recently become engaged to the daughter of a church elder. Then he made a mistake that found him cast out: He cheated on his fiancee with a community college classmate. The fury over Andrew’s experience—and his decision to publicize the church’s internal disciplinary procedures—has led to accusations by other Christians that one of the most powerful evangelical voices in the country, Mars Hill pastor Mark Driscoll, employs a cultlike leadership style. Now, for the first time, Mars Hill is speaking out in response to its former member’s charges.

Driscoll is an unusually polarizing figure within the American evangelical community. Though he can resemble a hipster ex-wrestler as he paces the stage in sneakers and jeans, his theology is old-school Calvinist. Driscoll reveres masculinity even in matters that seem merely aesthetic: He’s a fan of mixed-martial arts but calls yoga “demonic.” If Mars Hill’s discipline practices are indeed oppressive, it’s hard not to make the connection to Driscoll’s fascination with powerful manhood.

Perhaps unsurprisingly for a man this interested in structures of authority, Driscoll maintains a firm grip over his congregation. Mars Hill is nondenominational, which means it doesn’t formally answer to any outside institutional bodies, so Driscoll holds the power. He has preached against “sinning through questioning” and once said publicly he would like to “go Old Testament” on dissenters. He has reported that he can sometimes “see things” about his members’ past sins.

Now, as even fellow evangelical Christians express concern about how Andrew was shunned, the church must confront questions about whether its disciplinary practices are misunderstood and biblical, or disturbingly controlling. Is Mars Hill’s PR drama a lesson in how even the best institutions will have disgruntled critics, or a case of an increasingly powerful organization abusing its members’ trust?

Like most churches, Mars Hill’s right to exercise discipline begins with membership. (You’re not going to get quizzed about your sex life just for taking a seat one Sunday.) Upon agreeing to join the church, would-be members must sign a “covenant.” Part of that contract stipulates:

I covenant to submit to discipline by God through his Holy Spirit, to follow biblical procedures for church discipline in my relationships with brothers and sisters in Christ, to submit to righteous discipline when approached biblically by brothers and sisters in Christ, and to submit to discipline by church leadership if the need should ever arise.

Church members agree to “practice complete chastity before marriage and complete fidelity in heterosexual marriage by abstaining from practices such as cohabitation, pornography, and fornication,” and to refrain from drug use, drunkenness, and “other sinful behavior as the Bible, my pastors, and my conscience dictate.” The church says that a version of this contract has been signed by all members since 2007, one of several changes that some critics said were designed to concentrate power among Driscoll and a few close aides. Andrew (who asked that his last name not be used) told me in an email that he doesn’t remember signing the covenant, comparing it to a user agreement for iTunes.

Andrew first told his story in January to prominent Christian blogger Matthew Paul Turner, who posted it in two detailed parts on his website. According to that account, Andrew cheated on his fiancee, engaging in some kind of sexual contact short of intercourse with another woman. Racked with guilt, he quickly confessed to both his fiancee and another member of his small group. About two weeks later, he also admitted to having a premarital sexual relationship with his now ex-fiancee. Andrew told Turner he was forced out of his original small group, which is an important touchstone for most megachurch attendees (and a requirement at Mars Hill). For the next month, Andrew met with—and received texts from—many church representatives. He was given a new contract requiring that he write his “sexual and emotional attachment history with women” and share it with his fiancee; he was also told to give her, and his pastor, a list of his sexual and emotional sins. (Turner posted the document.) Instead of signing the new contract, Andrew announced he was leaving the church.

In Andrew’s account, Mars Hill responded by posting a three-page letter to the church’s online network the City, which Andrew describes as “Facebook for Mars Hill members.” The letter, posted on Turner’s site, included instructions on how to ostracize Andrew; having a meal or going to a concert with him were deemed “not permissible.” The document included examples of how to decline the ex-member’s attempts to reach out: “Andrew, I would enjoy time with you but I can’t because you’re under church discipline. You can join me if we can talk about your refusal to listen to God and the church.”

Turner’s headline calls this response “cult-like,” and he’s not alone in this opinion. Driscoll and Mars Hill have long been controversial in Christian circles (the New York Times Magazine once called him “American evangelicalism’s bête noire”). With Andrew’s accusations, the Christian blogosphere exploded in outrage. Bent Meyer, a former Mars Hill elder fired from his staff position for insubordination in 2007, told his own story for the first time publicly. One ex-attendee started a blog called Mars Hill Refuge where others “who have been wounded by their experience with Mars Hill Church” could share their stories. The Seattle alternative newspaper the Stranger published another account from an unhappy ex-member, who compared his experience at Mars Hill as “how people wound up drinking Kool-Aid.”

Before now, Mars Hill’s only response has been posting an excerpt on church discipline from Driscoll’s 2009 book Vintage Church on its website and an opaque tweet from Driscoll. But Justin Dean, the church’s PR and marketing manager, agreed to answer my questions by email to tell the church’s side of the story.

One key element that was not clear in Andrew’s original account, Dean told me, was that the letter was intended to be read aloud, not posted online, and only to a “handful” of people. Instead, the group leader received unclear instructions and posted the letter online, a move Dean insists was not meant to hurt Andrew.

Furthermore, says Dean, only the approximately 15 members of Andrew’s small group, who met regularly and knew one another well, had access to the letter on the City. (Though Andrew was blocked from accessing the City, he says the letter was available to a slightly wider circle, including his fellow security volunteers.) “His case was not shared with the full church and had, until he posted it publicly online, only been known by a handful of people who were involved in his life and cared deeply about him,” Dean said. (Confusing social-media privacy settings strike again!) He added that Driscoll was not involved in the case at all. Mars Hill currently has 5,417 members and just nine ongoing church discipline cases.

Ugly, divisive cases like this one can make the entire concept of “church discipline” seem medieval. But the practice has a long history in the church, including a passage in the Gospel of Matthew, and 16th-century reformers who named discipline as one of the three “marks by which the true church is known.” Ken Sande, president of Peacemaker Ministries, an organization that consults on Christian conflict resolution issues, compares church discipline to how a bar association operates. The bar polices itself, watching over members and holding them accountable. Church discipline can help intercept true predators before they do more harm and sends a message about the consequences of sin—a phenomenon Sande compares to when the bar association publishes the names of disbarred attorneys.

As a church grows from a tight-knit community to a group of thousands, discipline becomes more difficult. That’s why churches like Mars Hill encourage participation in small groups, in which members can be accountable to one another in their personal struggles. Moral development, as old-fashioned as that term may sound, can be a beautiful, transformative part of the work of the church.

Though experts say the practice of church discipline has been broadly on the decline for decades, cases of heavy-handed punishment occasionally make the news. In 2008, for example, the Wall Street Journal reported than a megachurch pastor in Nashville, Tenn., threatened to expel 74 members for gossiping. But “when church discipline is working well or rightly, it is respectful of personhood,” John Ortberg, the influential senior pastor of California’s Menlo Park Presbyterian Church, told me. “So it’s not coercive, it’s not manipulative, and it doesn’t build a culture that’s characterized by inappropriate levels of fear or shame.”

The question that Mars Hill members must confront is whether the atmosphere at their church is one of respect or shame. Dean says that the church would welcome reconciliation with Andrew, but Mars Hill is not backing down from its strict definition of repentance. The unspoken implication seems to be that Mars Hill itself has done nothing it needs to repent from.

Dean describes Andrew as “a man who cheated on his fiancee, lied about it, and only confessed after being pressed about suspicious details.” And Driscoll made it clear in remarks at a 2009 conference that he does not tolerate divisive “troublemakers” at Mars Hill. “You can really change the culture of a church by just removing a few ‘negatives’ and elevating a few ‘positives.’ Most of the ‘neutrals’ change. You don’t need to get rid of everybody most of the time,” he said.

Getting rid of Andrew may end up being a mistake for Mars Hill, though. Because of him, the chorus of troublemakers is growing louder.