I have never seen a dirty car on a used-car lot. We all know, of course, that shiny cars eventually collect streaks of rain, globs of mud, and bird droppings. Yet American marketing wisdom insists that every car for sale, no matter how old and battered, be presented at its shiny best. Lift the hood and you'll probably find that even the engine has been scrubbed clean of grease and dirt.

Realism only kicks in after you buy the car and begin to drive it. A few weeks later, the door to the glove compartment sticks, the valves rattle during acceleration, and a cloud of blue smoke puffs out the tailpipe. Somehow the car dealer found a way to mask those symptoms until you signed the contract.

It occurs to me that the church reverses this tried and true marketing wisdom. In certain ways, unwittingly or otherwise, we present our very worst image to the outside world, and then ask insiders to swallow a heavy dose of unreality. For some time now, I have been asking people I meet in airports or waiting rooms (those on the outside) what comes to mind when I say the word Christian. Often the response includes the prefix anti: anti-homosexual, anti-abortion, anti-pornography. The watching world sees Christians as strident people who try to impose their morality on others. In addition, we live with the church's historical reputation, for good and ill. Unbelievers cannot make sense of all the denominations, and they know about the shameful moments in church history, such as the Crusades, the Inquisition, the burning of witches. At least in the modern West, the least attractive side of the church gets most of the publicity.

Inside the church, the scene shifts. I have interviewed dozens of Christians, and heard from hundreds more, who tell me ...