Massi,
A man comes to you and says that he had a revelation that there is an invisible cupcake that orbits MARS. You can't see it, touch it, smell it, hear it, or feel it, but he insists with all his heatr that it is there. You say you don't believe him. Then he tells you What's your proof that this cupcake doesn't exist?
Can you prove to him it doesn't exist? How can you prove something negative?
Before you ponder over that, let me save you the trouble of doing so. The burden of proof is always on the one who claims, not one who doubts. God may very well exist, but as I said, it's very improbable based on all the evidence that is against his existence. Likewise, the man's cupcake may very well exist, but you can't see it, touch it, hear it, or feel it to know for certain. Thus, you have no reason for believing in it. But, if you do believe in it, that's called faith. With enough metaphorical pondering you may think the cupcake's existence is probable, and you may even feel a tingle inside your body that tells you it's there, orbiting merrily around MARS, then you go on to call it "educated faith." However, the fact of the matter is, you really have no real evidence for the existence of the cupcake...