This is something I've been kicking around in my head for months now. As with any physical-world metaphor of spiritual-world happenings, it falls short—there are many things about dialysis and transplantation that do not parallel salvation. But while the pitch of the story may be off-key, it hums along with the tune of redemption.
Julie had a condition which would end in death. Externally, this was hard to tell. Even for her, it was frequently hard to believe that anything was seriously wrong inside. It would have been easy to continue to ignore the signs and symptoms since they weren't present all the time. But the simple fact was this: Julie was sick and wasn't getting better.
She tried being good. Per doctors' instructions, she "avoided" foods high in sodium; she "avoided" foods high in cholesterol. She "cut back" on protein consumption in general. Sure—she wasn't always consistent, but nobody's perfect. Besides, it didn't seem that to err in her food choices really changed things one way or another. And in a real sense, it didn't. At best, good dietary choices made her feel a little bit better as the inevitable came.