Miracles are extraordinary events, coincidences, or phenomena for which there is no rational or scientificexplanation at the time. When there were few rational explanations for the unusual events in the natural world, the supernatural explanations had power. But there have been scientific explanations for quite a few miracles, since advancements in technology and science have allowed an understanding of the natural world and it's processes that was unthinkable at the time of the miracle.
There are explanations for every one of the biblical plagues. There were either parasites that caused awful effects on the human body or waterspouts that picked up frogs, transported them for miles, then dropped them somewhere else.
There are molds that form on grains, which cause episodes of violent insanity when ingested by humans. There were toxins and poisons that were not known, understood, or identifiable as the causes of horrific death and injury. Those who escaped the effects while others were not spared are highly likely to judge the event as miraculous.
There were accidents and natural disasters where a specific cause could not be found. In natural disasters and wars, where it appeared that everyone should have died, many lived, and the apparent "selection" was considered by some to be either protection or retribution that was directed at individuals from some supernatural source.
There are no explanations for certain images that are not visible to the naked eye, but which show up in photos, whether the photos are from film cameras or from digital cameras. There are no scientific explanations for many spontaneous remissions of cancers and tumors.
There are no medical explanations sometimes as to why a person was at near death or even appeared to be dead, then revived and recovered with a return to full health.
As a result, religious faith and belief in miracles is not absolutely threatened by the ability of science to provide secular, rational and tested proof for many of the fantastic and spectacular events that occur in our world or in our lifetimes. There will be more than enough of unexplained events that will be called miracles because there is no other explanation.
There are miracles that have not happened yet, and they are likely to be unexplained by science or rationality. There will also be fakers who convince others that they have evidence of miracles. As a result, science is not in danger of explaining all phenomena and events and all phenomena and events are not in danger of being put to rest with a scientific explanation.