Regarding healing, it's a murky subject... Pagan priests and shamans also seem to work, not to mention other world religions...
The argument based on evidence is also weak – for example, Muhammad testifies to Allah (don't tell me that it translates to "God"! I know! I'll even add that "god" is "lah"; "al" is a definite article – it turns out to be something like "the God" – "Al-lah." Theologically, these gods are completely different!). There are countless testimonies about the appearances of, for example, bodhisattvas, or, even more so, pagan deities!
I believe in God, but I can't say for sure why... I just... don't even feel it, I simply know (although this is a very presumptuous statement, I couldn't find a better word:()), that He exists...
Why is healing a murky subject??? What's so murky about it? Shamans and priests... it's debatable. This was a long time ago, and it's not the case now. If they were healers, why were they feared?