When I mention or write about the fact that I doubt miracle accounts, some people respond by sharing a personal story of how they, or someone they know, was miraculously healed from cancer, paralysis, or some other debilitating ailment. They then often end by asking: "Kevin, how do you explain that?", as if my possible lack of an explanation somehow strengthens their case for a supernatural answer. And I admit that when it comes to some of the personal, sincere stories I have heard about miraculous healings, I have no concrete explanations to offer. But does this fact strengthen the case for the supernatural? I don't think it does.
As explained in this video, someone who argues that something has a supernatural cause because it can't be explained is basically saying: "I don't have an explanation, therefore I have an explanation". Not only is this is contradictory, but this argument also uses human ignorance to strengthen the case for the supernatural. And this can't work, because any unexplainable event can have a myriad of possible, imagined causes, and each of these can be equally valid if we only appeal to ignorance. I can just as well argue that our inability to explain a miraculous healing lends support to the claim that it was caused by invisible aliens from Betelgeuse. Thus, at face value, an unexplainable event – such as a miraculous healing – should not be considered a supernatural event. Rather, we should label an unexplainable event as an unexplainable event; no more, no less.
There are some who claim to have evidence of miraculous healings, either as video footage, medical reports, or X-rays. But even if these sources are sound, they can't be used as evidence for God or the supernatural, but only as evidence that something unexplained happened. Because such evidence can only eliminate known natural explanations.
I think that in order for us to raise the status of a miraculous healing from 'unexplainable' to the more substantial 'supernatural', the person making the miracle claim will need take an additional step to eliminate unknown explanations, natural or otherwise. This can be done by providing evidence of a causal link between a specific supernatural entity and the event in question. This is more difficult, I think, because a person will first have to show evidence that the supernatural entity exists in the first place, and then provide some explanation of how this invisible entity is able to manipulate flesh and bone.
So, as an atheist, I might not be able to explain instances of miraculous healing, but this doesn't mean that such events have a supernatural cause.