[quote=So Boerd]
Of course. Let me make up some possible evidence... In this hypothetical, suppose there was a hand which materialized out of air and wrote "I am God" on the nearest available surface to them at the same time all over the world. Some instances were videotaped, however they can't make the hand appear again. Is this sufficient?
[/quote]

I think people would think that an impressive display of modern CGI technology. Quite nifty, but not sufficient. You must realise, Boerd, that miracles do not lead to belief and faith. It is a process which requires reflection and thought. Miracles help us along, but they are by no means a must.