I think you mean the Revelation 13:16-18 which states that no one can buy and sell without the mark of the beast. It’s not a currency but something that was implant or tattoo to people in able to make a transaction. While the world will have a single currency to transact.
OP did not include this on his thread but those two sects of religion do not have a full understanding of Cryptocurrency, they just concluded and preached that Bitcoin is the one being mentioned, but it's unlikely that it is because no government is controlling Bitcoin it used to be a computer chip or ATM in the past, but now with the growing popularity of Bitcoin they connect it to that verse in the Bible, this is one of the things that hinders the development of Bitcoin.
If this is true that some sects of religion are doing this then we should call them out to enlighten them about Bitcoin and ask them to explain why they have to connect to Bitcoin that bible verse.