Are miracles possible?
What is a Miracle?A miracle is a striking and religiously significant intervention of God in the system of natural causes. [1 p. 109]
Two Different QuestionsThere are two different questions, firstly “Are miracles possible?” and secondly, “Are miracles actual?” The answer to this second question requires knowledge of events in history. Some form of historical investigation is required in order to determine whether a miracle has actually happened. [1 p. 109]
However, nearly all people that deny that miracles have actually happened, have not done so because of historical investigation, but rather philosophical arguments; arguments that are supposed to prove that miracles cannot happen. [1 p. 109]
How does a person justify so strong a claim that no miracles have ever happened in the entire course of human history? Did they examine every alleged miracle story, sift through all the evidence on a case-by-case basis? Of course not; that kind of investigation would take lifetimes. How then could such a claim ever be justified? Only if their exists arguments showing that miracles are impossible or vastly improbable. That would free us from the need to take any evidence for miracles seriously, because we would already know that it is not really worth considering at all. [1 p. 110]
We therefore need to start by examining arguments for the possibility of miracles. This then allows us, or opens us up to examining the historical question of whether or not they really happened.
Arguments for the Possibility of MiraclesObviously, you cannot believe miracles have happened without believing that a miracle-worker exists. So behind the important question of whether or not miracles are possible, lies the even bigger question, “Does God exist?” If one does not believe in God, then you will not accept the miraculous.
The conclusion of the previous section “Does God exist?” is the foundation for the argument for the possibility of miracles.
Once we have established that God exists, there are two arguments for the possibility of miracles: one from the side of God, the miracle-worker, or the cause, and the other from the side of the world, or the effect. [1 p. 110]
Firstly, there is no defense against miracles in God’s nature, no assurance that God would not work a miracle. For if there is a God, he is all-powerful (omnipotent), and therefore would be able to work miracles. So there is no obstacle to miracles in God. If there is a God, miracles are possible. [1 p. 110]
Second, there is no obstacle or defense against miracles on the part of the world of nature. If God created it in the first place, that is, if nature is open to the possibilities of existing or not existing, then it is open to the possibilities of containing miracles or not containing them. In other words, if the author can create the play, he can change it too. And if the play is dependent on God, its author, for its very existence, then it is also dependent on him for whatever else he may want to do in it. [1 p. 110] If God exists, then He is capable of transcending natural law, of which He is the author. 
ConclusionFor those who battle to accept the possibility of miracles, the real problem is not so much with miracles, as with the whole concept of God. Once we accept the existence of God, there is no problem with miracles, as God is by definition all-powerful and fully capable of bringing them about. 
Once we have established that miracles are possible, we should be open to examining their actuality. Whether or not a given miracle has occurred becomes a historical matter that calls for investigation.  The rest of this Apologetic study asks you to do exactly that, to carefully and honestly examine evidences for the miracle of the Incarnation – God taking on human form.
What about Science and Miracles?The success of modern science in describing the world in terms of cosmic regularity has led some to rule out miracles as an outdated and impossible concept. This is an unwarranted philosophical assumption and not a scientific conclusion. 
Science consists of knowledge based on observed facts and tested truths arranged in an orderly system. Science operates by assuming certain things given, and an order or regularity that makes empirical (based on experiment and observation) investigation possible. [1 p. 112] Science depends upon observation and replication.
That is why questions like: “How come the world of matter exists at all – rather than nothing?” or “What caused the Big Bang – the absolute beginning of all material being?” are also not, strictly speaking, questions within physical science. This does not mean that such questions are meaningless, only that science cannot answer them. [1 p. 112] Scientific understanding is based on constant repetition of events. 
Miracles, such as God taking on human form or Jesus’ resurrection from the dead, are by their very nature unprecedented events. No one can replicate these, or similar, events in order to observe them.
A scientist who, say, believes that God caused the universe to exist has not abandoned scientific method, but merely acknowledges its limits. [1 p. 113]
Also, note that once we have established that God exists, we can conclude that that miracles are not in conflict with any natural law. Rather, miracles are unusual events caused by God, and the laws of nature are generalizations about ordinary events caused by Him." 
The question of whether miracles are possible is not scientific, but philosophical. Science can only say miracles do not occur in the ordinary course of nature.  It cannot determine the possibility of their existence.
For a interesting argument showing that the methodology and “laws” of science, actually support the miraculous, please see “Truth Journal, Miracles and Modern Scientific Thought” by Professor Norman Geislee . The following is a brief outline of his approach.
A typical argument against miracles is as follows
Is it not more likely that miracles never really occurred as described?As a miracle, by definition, goes against some law of nature, is it not therefore an unlikely event? It is therefore always more likely that the event never really occurred as described (or remembered)? [1 p. 111]
While miracles are certainly unusual, how do we know whether they are likely to happen or not? We only know this, if we have already decided whether or not it is likely that God exists - or that he would ever work a miracle. [1 p. 112]
To assume that miracles are unlikely, one is assuming that God does not exist or does not intervene in nature, and therefore the event reported is not a miracle at all. [1 p. 112]
Suppose, for example, that we are asking whether Jesus rose from the dead. We need to consider whether to believe the various reports of his resurrection that are recorded in the New Testament. It won't do to dismiss them simply on the ground that "that sort of thing has never been observed." We can't know that unless we already know that the reports in the New Testament are mistaken. 
While miracles may be unusual, this fact does not allow us to conclude their impossibility – that they never really occurred as described. We should still be open to honest and careful historical investigation of their actuality.
(c) 1999 - Richard Helsby