Dale Rosenberger dares to go where few mainline pastors want to these days: into the thorny question of pastoral authority. At a time when many mainline churches are struggling for identity, it can be tempting to define ourselves by what we are not: we are not fundamentalists; we are not charismatic; we are not places where anyone will tell you what to believe or what to do. Into the meandering vagaries of such theological small talk stomps a seasoned United Church of Christ pastor.

Rosenberger answers the question people have asked him over the years whenever he has made a claim for the authority of the gospel, “Well, who are you to say?” He points out that when most mainline Christians answer that question, it is with hesitation or, worse, a pretense of objectivity, shaped as we are by the expectation that we approach the subject coolly. Rosenberger wants more ardor brought to the task. “To insist that our conversations of faith remain ‘objective’ is to inoculate against passionate involvement,” he writes. “It is like telling Louis Armstrong he needs to be a little more restrained with his trumpet if he expects us to listen to his music.”

Rosenberger does not restrain himself. This is crisp writing, spiced with real stories from the ministry that condemn the author as often as they do the church. Asking why churches prefer to be social service agencies, neighborhood glue or clubs when they are called to be “outposts for the reign of God,” he tells a story of his own congregation. In its desire to do good, the congregation told its immigrant neighbors about the tax code, health care and the public school system, but never told them about Christ or Sunday morning worship. Rosenberger names trends we have all seen, and he names them boldly, with honest examples that are painfully characteristic of mainline malaise.

They are also very real. In Who Are You to Say? there are no sacred cows, and there is much that may convict and offend traditional mainliners. At times Rosenberger is too hard on liberals who live out their faith rather than proclaiming it; after all, many have moved closer to God through the life of faith well lived, and much of that work for social justice and equality can hardly be dismissed as a failure of nerve. There were times when I found myself wincing at his critique and thinking that a better title for the book would be I Can’t Believe He Said That. But this strong, argumentative writing is for a lukewarm church curdling in the culture wars. And most important, it comes from one who labors lovingly in the vineyard he criticizes. “I tell this story about mainline-liberal Protestantism in its well-ordered, broad-minded, sophisticated, latitudinarian fustiness because that is where I am blessed to serve.”

As creatively cranky as this book is, it ends hopefully, with a challenge to clergy to release themselves from the respectability of the profession and embrace the strangeness of the call. Rosenberger remembers his Yale Divinity School professor William Muehl, who somehow knew that after one semester of theological education the students would return home and spin tales of how what they were doing fit in with the world. They would say, “I engage in interdisciplinary studies around cross-cultural perceptions of the Infinite, how they impinge on the human condition, and their shared commentary upon contemporary society as a numinous meta-narrative,” instead of the more realistic, “I went to seminary and will likely end up a pastor because I couldn’t get into University of Michigan Law School, local churches sorely need pastors and right now I can’t think of what else to do with my life.”

By acknowledging—sometimes with confrontation, sometimes with humor—pastors’ fallability, Rosenberger reminds us that pastors’ authority in their role is ultimately not about the pastors themselves, and therefore the authority may be easier to claim. With a reminder from Martin Copenhaver that the church without God would be the worst of both worlds, Rosenberger calls pastors to proclaim the gospel and to reengage theologically.

“We need more ‘pastor-theologians’ in this sense as opposed to technicians, Rotarians, managers, huggy-bears, and game show hosts,” Rosenberger asserts. “Our calling is not to put a Christian tint on the world’s ways of salvation. . . . Our calling is to proclaim and interpret how in Jesus’ death and resurrection God has already saved us and now frees us and the world to live in light of God’s saving acts.” This shouldn’t be a tall order, but of course it is.

Because he refuses to allow niceness to trump passion, many of Rosenberger’s barbs will sting. You’ll feel yourself answering back—and even asking, “Who are you to say?” But that’s what Rosenberger wants: a vital, hot debate about authority in a mainline world of tepid ecclesiastical niceness. It may be just what we need.