Been a while since you've posted GT. Happy to see you.
“The correct prayer is therefore never a prayer of supplication, but a prayer of gratitude. When you thank God in advance for that which you choose to experience in your reality, you, in effect, acknowledge that it is there…in effect. Thankfulness is thus the most powerful statement to God; an affirmation that even before you ask, I have answered. Therefore never supplicate. Appreciate.”
― Neale Donald Walsch, The Complete Conversations with God
I have no doubt that faith held by the sick can heal, IF the healing is meant to happen. I also know that for some people, the sickness is meant to be. A dear friend on Medium, a young woman, was diagnosed with terminal cancer a couple of years ago and her spirit guides (and I do mean not incarnated spirits), which she channels herself, have made it clear that she will not be cured.
I wrote a piece recently that includes stories of metaphysical healing and the power of faith. You might enjoy it https://medium.com/channspirations/this-vivid-dream-saved-esther-raabs-life-ed37b1637d23 and several other recent titles in my profile should you peruse them.