I also believe in the power of prayer and that (spiritual/faith) healing is very real as it can and does help people (I am a trained Reiki Healer and I have also received healing in a Spiritualist Church) but I would never advocate not going to see a doctor/specialist to anyone who is concerned about a medical problem. Generally I see spiritual/faith healing as being able to work alongside conventional medicine.
All the Church needed to do was to put a disclaimer on their leaflets, about people seeing a qualified medical practitioner if they are concerned about a medical problem, or it could give the impression that spiritual healing can cure anything for anyone, and this could have disastrous consequences.