The Christian belief system is founded upon miraculous events. Without miracles, there would be no Christianity. In particular, the events surrounding the life and death of Jesus are thought to be miraculous, from the pregnancy of his virgin mother, to his rising from the tomb after death. Indeed, it is impossible to be a Christian without believing that these miracles are real.
At the same time, it is interesting to note that there is little agreement among Christians on what constitutes a miraculous event, or when and where such events have occurred, even among the various tales found in the bible. Was the parting of the Red Sea really a miracle, or could it be explained by natural forces? Could the destruction of Sodom and Gomorrah be due to meteor strikes? There are many Christians who think that God directly caused these events by suspending the normal laws of nature, and others who think that God brought about these events without actually violating natural laws by creating the necessary conditions and allowing natural laws to take their course.
What exactly is a miracle? A dictionary definition says that a miracle is an event that can't be explained by recourse to natural laws, but must be a result of the intervention of a supernatural power. There are certainly some Christians who agree with this definition. Here, for example is an article in the Christian Courier by Wayne Jackson, who defines miracles pretty much according to the standard definition. He says that the biblical miracles occurred for the purpose of confirming and validating the message of the bible. He also believes that there are no modern-day miracles. So-called faith healings are either faked or explained by natural phenomena.
It is interesting to see arguments about how bizarre or unusual a miracle might be. Richard Purtill argues that the biblical miracle claims are not so extraordinary as to be perceived as over-the-top, by comparison to the outlandish claims made by other faiths.
The point is this is what you get when imagination goes to work on a historical figure in classical antiquity; you get miracle stories a little like those in the Gospels, but also snakes big enough to eat elephants, kings and emperors as supporting cast, travelers’ tales, ghosts and vampires. Once the boundaries of fact are crossed we wander into fairyland.So according to him, we can discern true claims of miracles from fantasies, because talking donkeys, walking dead people, and water turning into wine are all within the bounds of reason, but huge snakes are not. On the other hand, there are some Christians who make essentially the opposite argument - that Christian miracles are superior in value to the relatively lame miracle claims made by others in antiquity. Jason Engwer makes the case for this in his blog. Depending on how you look at it, Christian miracle claims are better because they're either less outrageous or more extraordinary than the claims of other faiths. Go figure.
At the other end of the spectrum from Jackson, there are Christians who define a miracle as the actions of God, working through nature to bring about events that are unusual enough to get our attention. In this interview, Craig Keener defines miracles in this way. For example, he says of the parting of the sea: "God did it through a strong east wind. So technically it's not a violation of nature". Keener thinks that David Hume was responsible for creating the false modern conception of miracles as a violation of nature - something contrary to human experience.
While it may be true that the advent of modern science established an understanding of "laws of nature" that were not previously known, even in biblical times, people had a sense of what Hume called "uniform human experience", and were usually able to discern something natural from claims of things that were supposedly miraculous, and this is what Hume was talking about. In fact, it wasn't until we had a modern sense of natural laws that people like Keener were able to concoct explanations of miracles that could be seen as consistent with those natural laws. So his criticism of Hume seems rather misplaced.
A key point about Keener's definition of miracles is that his denial that miracles are violations of natural laws is simply incoherent. It makes no sense to say that God intervenes to bring about some result without violating any natural laws. Consider a situation where outcome X would occur in the absence of any divine intervention. That is to say, if the laws of nature take their course, X would result. But God intervenes, and causes outcome Y instead. God is making something happen that would not occur under the laws of nature. Outcome Y could only happen if the normal laws were suspended or violated in some way. And this is true for any miraculous event, no matter if there could be a conceivable natural explanation for it. If it is accomplished by divine intervention, then nature has not taken its course. A faith healing, for example, may be explained in natural terms, but if you want to claim that it is a miracle, you must agree that God has caused something to happen that would not have happened under ordinary natural laws.
Furthermore, Keener thinks that Hume's admonition against trusting claims of miracles involves a circular argument, because "he's arguing on the basis of uniform human experience that we can't trust miracle claims, and at the same time these miracle claims represent part of human experience." But his argument that Hume used circular reasoning is wrong, because while claims of miracles are common in our experience, the actual events depicted by those claims are not. All we really have to go on are the stories of people who say that they or someone else had this miraculous experience. And people are known to be untruthful. So why should we trust them, given that we never get to experience these things in person? They are in fact outside of our uniform human experience.
Case in point: One of Victors' commenters thinks that this is "impeccable" evidence of miracles. It is a story from the Catholic church about a supposed faith healing, that was declared to be a miracle by a panel of doctors and theologians appointed by the Vatican for the purpose of confirming a miracle in order to canonize a prospective saint. Seriously? What if the same story had been told by a Hindu (or some other) religious organization? Would he still consider it to be impeccable evidence of a miracle? We already know that the Catholic church is willing to seize upon practically anything in order to "comfirm" the miraculous works of someone it wants to canonize, as I have discussed previously.
The bottom line is that miracle claims are just claims. Hume was absolutely correct to say that we should regard them with skepticism. If we don't experience any extraordinary events ourselves, and we don't know of any such reports from reliable, unbiased sources, then we have no reason to think they are true. The biblical stories were written for the purpose of bringing people into the fold. The Church believes that canonizing popular figures like Mother Teresa serves the same purpose. But they aren't reliable, unbiased sources. Show me a real miracle that I can see for myself - not some story about what someone else claims to have seen, but can't be verified - and then I'll have reason to believe.