I don't believe in religion, I don't believe in God, and I most certainly don't believe in miracles. That being said, despite my disbelief in deity, it is not uncommon for people to be perplexed as to why I still don't believe in their personal "miracles". Here are five reasons to best explain why I don't believe in the miraculous (being defined as "a marvelous event manifesting a supernatural act of a divine agent").
Reason 1: Lack of proof
Theists often say that they have proof of miracles in the bible. What they do not realize is that their holy books prove nothing. The miracles of Moses, Jonah, and Jesus have no more physical proof behind them than the fairy tale "jack and the beanstalk". If you believe that Jesus raised Lazarus from the dead, you can only do so by faith, there is no way to prove that that event ever occurred. Some people respond to this with the notion that we need to take the writers word for it. Although it is true that we rely on the method of "taking their word for it" when recording historic texts, it's important to note that I hold those other texts up to the same level of scrutiny. I take peoples word on the documentation of napoleons journey, but if I read that napoleon raised someone from the dead, or turned water into wine, I would be very skeptical.
Another problem with religious texts being the basis of proof for miracles is that there is great contradiction when people compare religions. For example, it is rare for a Christian to believe in the miraculous account of Muhammad splitting the moon. Likewise, Muslims don't tend to believe in the miracle of the atonement of Jesus Christ. People tend to believe in the miracles they were taught growing up, and tend to be skeptical of other religious claims. The only thing opposing religious texts hold in common is their lack of evidence to prove the miracles depicted.
Reason 2: Coincidence
Let's say we roll seven dice, and we get the numbers 5, 3, 2, 1, 4, 2 and 3. Typically, this would be regarded as a regular or somewhat insignificant outcome. Lets say we roll again and we get all 6's. This outcome typically gets more attention, and is often regarded as a rare occurrence. The fact is however, that if you roll seven dice, you the have a 1 in 279936 chance of getting either the first roll, or the second roll. In other words the probability of either outcome is the same.
Many people argue that there have been too many "coincidences" occurring, or leading up to an event for it not to be a miracle. For instance, a doctor may happen to be in the vicinity of a horrific accident, and therefore be able to save someone's life that would have otherwise perished. Although the scenario is unlikely, it doesn't mean it is miraculous. In the year 2004 there was an average of 16,934 car accidents reported to the police each day in the United States alone. With such a high number, you are very likely to get a "miraculous" outcome sooner or later. For every deadly car crash that happens in front of a doctor, there are many, many more people involved in other bad accidents that aren't so fortunate. Some say they have seen too much coincidence not to believe in miracles, I see coincidence as well, the difference is I believe in coincidence.
Reason 3: Selective Labeling
It is not uncommon for people to identify miracles in their daily life. From beating cancer, to getting a job, to finding your car keys, many people choose to attribute select events or occurrences to "miracle". Typically, miracles in a personal sense are defined as events that are seemingly unlikely. However, that being the case, people are very selective as to what they deem as a miracle. For instance, if a child was diagnosed with a deadly illness and was not expected to survive, but then gets better. It is likely that the family will call it a miracle. But if a child is diagnosed with a minor illness, but then unexpectedly runs in to complications and passes away. Then the family would not call it miraculous. People only deem seemingly unlikely events as miracles if the outcome seems positive.
Sometimes one man's miracle can be another mans horror. For example, when Hitler survived an assassination attempt during the Second World War, it is likely many Germans regarded it as a miracle, while the allies hardly felt the same. Someone's personal idea of a miracle is just that (personal that is). We have no official barometer as to determine what seemingly unlikely occurrence is miraculous, coincidence, or unfortunate.
Reason 4: The laws of nature
Many define a miracle as "a perceptible interruption of the laws of nature". The very core of biblical miracles pivot on the idea that the laws of nature can be tampered with, seeing as raising the dead, turning water into wine, and walking on water are all impossible within the bounds of natural laws. Again, reverting back to reason one, we have no evidence to show that biblical miracles ever occurred, as well as no proof of miracles meeting this definitions standard in modern times.
Some select theists take a different road by stating that hundreds of years ago, people would have laughed at the idea of jet fighters, computers, or the Internet. The intent being to imply that any miracle in the bible that seems impossible occurred within the bounds of natural laws. Either way you go, neither position proves anything, or explains anything as to how the miraculous events occurred. The irony is that every electronic piece of equipment they own, relies on the assumption that natural laws aren't manipulated or broken. Yet they still choose to believe in miracles.
Reason 5: Stolen credit
Too often people label things as being an act of God, when they should be giving credit where it is really due. If someone recovers from an illness, it is not because God performed a miracle, it's because the doctor did his/her job. If someone pulls over and helps a mother with a van full of children change a tire, it's not a miracle, it is someone going out of their way to help someone else. Identifying God's hand in everyday life can often come at the expense of not giving credit where it is deserved. People even often short change themselves; too often people attribute divine intervention, or miracle to the things they have accomplished. If you score well on a test, perhaps it's because you studied. If you get a good job, perhaps it's because you applied yourself. Maybe we need to start believing less in God and miracles, and more in others and ourselves.