I hadn't been inside a church for three years. I'd seen no sanctuary, no cross on the wall behind the pulpit, no pews, no stained glass, no engraved communion table. For three years at Heritage Church in Aurora, Colorado, I led worship inside a box-well, actually an elementary school gymnasium.

Instead of ornate banners declaring truth about God, the walls of the "sanctuary" were lined with sports posters and exercise equipment. Four regulation basketball hoops hung above us, and volleyball poles congregated in a corner-symbols of a competing American religion. The orange, all-purpose carpet had enough out-of-bounds lines to play most any sport. The mercury-activated lights hummed as loud as a swarm of bees.

Yet my fate wasn't unusual. Box churches are popping up all over-in gymnasiums, recreation centers, and storefronts. Heritage Church was in a building program, hoping one day to trade our box for a sanctuary. In the meantime, we had to face an important issue: Could we effectively worship ...