OK, so as an atheist I have to look at differing opinions of the 'believer'. So lets have a look at satanism. And in particular - summoning demons! Yay!
I have been warned by many people over the years about studying, learning or even having a fleeting interest in anything considered remotely 'occult'. But it is fascinating. (That is EXACTLY the thing I should be worried about, apparently...) And they say the devil has all the best tunes - probably because 'christian-rock' is so utterly sh*t.
It has been suggested that atheists do the 'devil's work' with all our disbelief, and criticism and I'd thought I'd balance the situation.
If there is evidence of ghosts, spirits, demons, djinns, fauns, faeries etc. then the argument for an afterlife / heaven / higher plane of existence becomes a better probability. Interestingly, if you believe in a god, then by default you are expected to believe in the personification of evil. (As if the original idea wasn't silly enough. Talking snake! Tsk!)
The site I browsed was here. And I can't fail to be impressed with the excuses if you fail to summon a demon. But if you are looking for 'proof'
BTW - You can tell if a demon has visited by the following:
1) There might be a breeze.
2) You might get a 'feeling'.
3) A candle might flicker.
4) You might have a dream about a demon.
Oh yes. I am SO convinced. ( But then I did dream about pasta once which can only prove the existence of the Flying Spaghetti Monster. )
There are some gullible idiots out there. But hey! If any satanists are reading this, please feel free to send me any demonic proof. Since, according to christians, I am going to be sent to your mythical retirement home, maybe even some kind of 'welcome pack' perhaps? Or even an imp or two? Maybe my shoelaces won't untie!!! Oh what devilry!
ps. In satanist's defence, the ONE I have knowingly met and talked to was quite a nice chap with strong moral beliefs that I would not have expected. He did have a bit of hero worship for Hitler - which failed to impress me but you seriously could not have picked him out of a crowd.