It's amazing how much easier it is to demonstrate an extraordinary claim when the claim is actually true.
Some Scottish guy claimed he could make a substance called penicillin with antibiotic properties. What evidence would convince the skeptics?
Ancient astronomers "prophesied" about the timing of eclipses hundreds of years into the future. Again, without divine help, how could they possibly convince the skeptics?
We have simultaneous video footage from multiple observers at different angles of the most exotic atmospheric phenomena. And yet we can't confirm a SINGLE Virgin Mary sighting, of the hundreds that are reported? Imagine if reports of the Northern Lights were mainly from the 1st century AD and if most of the reports today came from the least literate societies with the highest concentrations of "Northern Lights worshippers". Wouldn't that be peculiar?
Religious claims *should* be easily proved if they are true. And yet, we need faith in order to see the evidence. No modern miracles or prophesies allowed -- especially not ones verified by technology (video/sound recording). It's a lot like a magic act, the tricks look more convincing if you want them to be real magic, no peeking behind the stage, and the good magician only performs a trick once, and you can't interrupt and examine it the one time it is being performed.
And then there are so many documented cases of fraud, delusion, or misapprehension nearly every time we are able to examine a religious claim properly. At some point the question must be posed to the *believer*, "What kind of evidence would convince you?"
But really the question of God is a much more respectable and interesting philosophical question, to me, and much more difficult to answer, than the question of "What kind of evidence would convince you Mormonism is true?" (Just an example -- apologies to Katz!
) Plenty of brilliant minds have concluded there is a God or at least some sort of designer. I have a different opinion. But thankfully the question about specific religions is much easier to answer than the question of God/a designer. I would not say Mormonism (for example) lacks evidence for its truth, I would say there is a mountain of evidence that demonstrates it is a complete forgery. Again, the question must be posed to the believer, "What kind of evidence would convince you?"