London’s Café Rendezvous has nice lighting, comfortable couches, and the smell of coffee in the air. What it doesn’t have are prices. Originally started as a business by a local church, the café was transformed a year after it started. The managers felt that God was calling them to do something radical—make everything on the menu free. Today you can order a coffee, cake, or sandwich without cost. There isn’t even a donation jar. It’s all a gift.

I asked the manager why they were so generous. “We’re just trying to treat people the way God treats us,” he said. “God…