My guess is that the supernatual phenomena written about in the Bible is meant to be of a symbolic nature, though in some cases I have heard and read about natural phenomena that is also evident, such as the parting of the red sea. I think that this is said to be a natural occurance, or perhaps was so in ages past. The serpent and the staff always sugests the cadecus [sp?] to me.

Even the miracles of the new testament are more relavent symbolicly. There could always be a natural explanation for many of these events. This is not to say that charismatic healing is not a miracle.