Pastor Roger Mendelssohn prayed for a megachurch. In the dark of his empty sanctuary at New Hope Christian Fellowship, he asked God for fame, for reach, for a platform worthy of his voice.

Something answered. It wasn't God.

The next morning, his nine-year-old daughter Sarah was diagnosed with a brain tumor.

The church doubled its membership within a month. The Southern Baptist Convention offered syndication. A sick child is the most powerful marketing tool in American Christianity, and Roger wielded his daughter's suffering like a professional. He rehearsed his tears in the mirror. His wife Leigh Anne discovered cocaine and stopped visiting the hospital.

Sarah lay in her bed, alone, watching her parents build careers on her dying.

Then the visitor came. Not a doctor. Not a chaplain. A friend who spoke to her like she ...