of course other ways to prove supernatural.
On the flashy side:
You can turn off the sun.
appear in the sky to everyone at once and say follow x book. (2 minutes per generation or so out of your schedule)
Regrowing limbs only for the faithful.
have people change color when they sin and return when they attone for the sin. (this might be good for police work as well)
The mustard thing would be pretty cool. pray for a mountain to move and it does...
On the passive not so flashy side:
You could make people who follow the word have demonstrably less suffering (peaceful death, old age, less dissease, lower childhood mortality...) Now when you look at muslims, bhudists, atheists ... lot in life and say hey perhaps there is something to this christianity (insert true religion here) thing.
Leave Christian (or insert true religion) houses stand in the midst of a tornado. You can still get your killing in and prove why you cursed the other people. (this leaves it up to you to see the pattern but it is there for all to see if they look)
The absolute lack of this kind of demonstrable evidence is exactly why I say faith is worthless
. For these believers (who have assumed their holy book in advance) they have been SOLD on the idea that when they have doubts, when they see no good evidence, or when they notice inconsistencies and/or direct contradictions to these extraordinary claims they should just have faith.
In other words, they bought into the idea that they should just keep believing, in spite of the fact that the evidence goes in the opposite direction of their assumed worldview, and interpretation of ancient texts. This is one of the things I cannot stand about religious apologists (whether of Christianity, Islam, Hinduism, or otherwise). They just keep assuming their view and trying to shift the burden of proof onto those of us who reject that view. Somehow, they think it's OK to pass the buck off onto anyone who doesn't agree. It's the, "Well, if you don't agree then your just blind"
fallacy (which is, yet again, another attempt to assume their biblical interpretation in advance).
And one of the most hilarious things about this is that if a salesman came to their
door and started using their
same type of faulty reasoning (obfuscating, shifting the burden, equivocating on terms, using the argument from ignorance, etc), to support a particularly "magical" product, they would quickly reject the salesman's irrationality and appeals to emotion. But they didn't do this when their parents sold them! Still too, claiming they had some "experience" with some alleged invisible entity called Yahweh only turns them into another salesman. It's the worst kind of network marketing scheme!
Again I ask, how is their claim any different from superstition?