There she was, walking toward me up the church aisle. Mary gave me my first job as a teenager—modeling clothes at fashion shows for her plus-size boutique—and I'd heard she had gastric bypass surgery since I'd last seen her. Indeed, half of the Mary I'd known approached.

"Lisa, you've got to talk to your doctor," she said. "Really, you should consider having a gastric bypass. I feel fabulous." Mary was nothing if not to the point.

"I'd rather die!" I told my sister.

Five years later, I almost did die after having weight-loss surgery. I woke up in the recovery room to strains of America's "Sister Golden Hair," an auspicious start if ever there was one. But within hours, I was pale and fainting. Eventually, I was diagnosed with a blood clot in my lungs. And over the following months, I contracted pneumonia, hemorrhaged, and needed three blood transfusions.

One-and-a-half years later and 100 pounds lighter, I still feel ambivalent about going under the knife in a bid to lose weight. The hard questions that led up to surgery still linger.

I've long been aware of the extent to which food has defined my person—for good and for bad. Considering surgery meant considering the death, or at least the maiming, of the vision of myself to which I'd grown accustomed.

But fear of losing my identity quickly gave way to questions about the theological ramifications of surgery: What would it mean to have a doctor section off a portion of my stomach and then reroute my digestive system?

Gnostic heresies be damned; bodies matter. God took one on. The resurrection of one is the locus of my salvation. Would seeking to control my own in this heavy-handed manner signal a loathing of my physical self?

On the other hand, in Matthew 5, doesn't ...