I see faith as residing on our emotional side rather than the reasoning side. For all of us, our visceral reactions come from the emotions and we merely use reason to justify our decisions. Occassionally reason can temper, or modify our behaviour.
Not all illogical choices are immoral! Many of us chose our life partners that way!
Selecting the bible over a medical textbook to perform medical procedures is stupid, not immoral. Conducting a medical procedure that could lead to harm is immoral. There's a difference! We still have priests anoint the sick with oil, but they do not stand in the way of modern medicine. For the patient, even though such an anointing is archaic with no medical backing, it may provide solace.
We see modern medicine not standing in the way of many illogical health choices today including a wide range of diet schemes, herbal, micronutrient, anti-gluten, anti-dairy, and other "natural" cures. As long as these schemes don't harm the patient or prohibit the patient from accessing conventional medicine, they are left alone. Why are they left alone? Because as long as they do no harm, it is not immoral!