There are religions today that still preach that their deity has the power to heal people, and they need only have faith that it will occur. This type of religious belief in miracles is called faith healing, and there have been recorded incidents that it does work. While some modern scientists have debunked some cases, others have found that the mind can make changes to the body that is not explainable with modern science. Whether or not they should be considered miracles is left up to those within the religious community.
The mind of man is an area still undergoing a great deal of theoretical work to explain how it controls the body, and scientists do not have all the answers. While there are now many machines in use to assist them, the functions of the brain are not always easy to decipher. When medical miracles are discussed, it can often be these same rational professionals who are willing to take a closer look to see what they can discover.
While few people are aware of it, their minds are more powerful than they might think. The control they exhibit over every area of the body is taken for granted, but it can make a profound difference. Scientists are often of the opinion that faith healing works through the control of the mind over the physical being, but they are unable to define the exact mechanisms that are at work. Many believe it will simply take more time before they can adequately explain the interface between mind and body, but they do accept that those of great faith have had incidents where their body has been healed.
There are many people who believe scientists are in the business of debunking every deity on the planet, but their goal is to simply understand how the physical world works. To a scientist, explaining the ability of the mind to heal the body through a particular religious belief is a miracle they want to be able to repeat on a regular basis.