By Lidia Kozenitzky, available from http://commons.wikimedia.org/wiki/User:Effib
Why are supernatural miracles clothed in the natural? As we learned in Parashas Beshalach, where the splitting of the Reed Sea was not instantaneous, but took a night of strong winds which gradually brought about the split, and where the descent of the mann was clothed in lower and upper layers in dew, which was unnecessary in order to preserve its freshness. In Parashas Vaera, Moshe's staff turning into a serpent was duplicated by Pharaoh's magicians upon their own sticks, and both plagues of blood and frog were also able to be duplicated by his magicians as well.
Why does Hashem bring about miracles in such manners? Why would He impress mankind with his wonders and yet allow them to think that the wonders are simply nature that can be manipulated by mankind? The answer lies in our freedom of choice to believe. Hashem will never take away our freedom of choice. Each of us is given the power of choice to believe that Hashem brought those miracles or not. If we are unclear in our perception of the miraculous events, we will surely try to justify their happening through nature or science or some other explanation. We can see this today in the global events affecting the whole world, which many of us believers, believe that it's part of Hashem's revelation to the world, while many others still try to find explanations and excuses for them, such as global warming, global cooling, solar storms, USDA, etc.
For the sun, the moon and other celestial beings, they perform their tasks exactly as Hashem commands them, because it's very clear to them who's the Boss and what the consequences are should they not follow through with their tasks. To the rest of us, it's always not so clear as to why we should or should not follow Hashem's commandments as dictated to Moshe Rabbeinu in our Holy Torah. We have the power to exercise our free will and we need clarity in order to choose wisely.
For a full treatment of this lesson, please watch this video, "The Nature of Miracles".
