Since this old topic (judging by the date 

 ) has been brought up again...This is what I wrote in a different topic, but I'll copy-paste it here:
I think that it is obvious that Gandalf was no match for Sauron in terms of sheer power. Tolkien himself sort of said this in letter #183(This was written as a note, so I only put in the actual note and the sentence that the note was referring to. And the passage is talking about Sauron):
	Quote:
	
	
		| ...But he went further than human tyrants in pride and the lust for domination, being in origin an immortal (angelic) spirit.* 
 *Of the same kind as Gandalf and Saruman, but of a far higher order
 | 
	
 I interpret "far higher order" meaning that Sauron was a far greater Maia than Gandalf or Saruman. The "same kind" obviously refers to the fact that they were all Maiar.