So much of this, if not all, is case-by-case basis. If one wants
  to go extreme and say, "either medical treatment *or* prayer"
  well, for the majority of either side, it's ridiculous. To say,
  "I don't want your prayer at all!" is ridiculous, although not
  as ridiculous as, "I refuse ALL modern medical treatment". Heck,
  even the Amish, who avoid contact with the English and handle
  most medical emergencies themselves, WILL resort to hospital
  care when absolutely necessary. Seems like a reasonable
  compromise. Then again, they have bad teeth and do pullings
  instead of dentists, but maybe they should cut down on the apple
  pies. Whatever. So, once you leave the obvious extremes, you
  have narrower margins. Let's go chemo vs radiation. It depends.
  My mother's best friend for years is one of the longest
  survivors of thyroid cancer. She's one of quite literally a
  handful (less than 5 last I heard) that had their treatments in
  the late 1970s and are still around and fine. In her case, it
  was radiation-only, no chemo. Does that mean that chemo is bad?
  No. Just a case of someone who didn't use it and it worked out
  for. She also prayed a lot being a devout Catholic. Now, to me,
  I wouldn't say, "Oh, she prayed and therefore it cured her",
  just as I wouldn't say radiation only cured her. But I can say
  she didn't do chemo. Correlation? Yes. Causation? No. Would I
  say that prayer did nothing? No, I can't say that. Some people
  can say that - that's their choice, but I don't know. I was
  raised to believe in the "power of positive thinking", so I'm a
  product of my environment as