My personal belief is Bitcoin by itself is good. Keep that in mind.
Did you know that Bitcoin may be predicted in the bible? Some Christians may believe Bitcoin to lead to the mark of the beast:
Revelation 16 And he causes all, the small and the great, and the rich and the poor, and the free men and the slaves, to be given a mark on their right hand or on their forehead, 17 and he provides that no one will be able to buy or to sell, except the one who has the mark, either the name of the beast or the number of his name. 18 Here is wisdom. Let him who has understanding calculate the number of the beast, for the number is that of a man; and his number is six hundred and sixty-six.
There is a man who injected himself so he can walk around with his wallet inside his hands:
http://arstechnica.com/business/2014/11/man-has-nfc-chips-injected-into-his-hands-to-store-cold-bitcoin-wallet/"....For the last 10 days, Martijn Wismeijer, a Dutch entrepreneur and Bitcoin enthusiast, has lived with an NFC chip embedded in each hand. One has data that he’s constantly overwriting; he can put his contact details in simply by having another person scan his hand with an NFC-enabled phone. But the other contains the encrypted private key to his wallet....."
If that was the case, the world would have to accept Bitcoin as a global currency, and also FORCE people to use it over any other currency and get the mark. That would still be quite a while off.
I'm so interested with this reply, and never imagined about that before. But I'm not sure to believe the thing that was told in Rev 16 is bitcoin. And so I can't find the 666 number in bitcoin.
This is the theory:
The number is the mark of the beast. And really, the idea is someone (the antichrist or beast) will require people to have this mark, in this theory, the mark will be your private key, in the form of something in your hand, as seen above in the picture.
The beast is seen by it's number 666, not the mark. Bitcoin would be a tool, the private key in hand would be the mark, not the actual problem. Except you shouldn't have the mark on your body. Using private keys not forced on your body would be ok, in this instance, I believe. There is nothing wrong with money. Bitcoin would not be considered evil.
It's just that it would be the tool, used to unite the world (the deceiver will come to unite the world together like New World Order, on the other hand Jesus will be coming to divide the believers from the evil anti-christ and anti-christ followers, the deceived).
It's a sign to find out who the beast is. Whoever would require people to use the mark on their body to sell or buy (and there would presumably be no goods for sale, without the use of the mark to buy, leading to black markets where you can buy without actually having the mark).
If you believe this, it's easy to believe Bitcoin will become huge. It would only start to be a problem if people were forced to be associated with their private keys into their bodies.
Edit: It may be that the mark when put into the body, will be combined with something else, like multisig addresses, where the other part needed to be used to withdraw funds will be the name of the beast or the number of the beast.