Anyone can read the warning in Revelation about the Mark at the end of chapter 13. But notice that the sanction is economic- those without the Mark will become economic outlaws and forbidden to participate in the normal economy.
Such people will not be able to hold legal jobs or even own a home because they will be unable to pay taxes, insurance and utilities. Even today, parents in a home without running water or electricity face State seizure of children for having a “unsafe” household.
A cashless society implies real-time debit card use. This means the State would be able to monitor all card use in real time. Thus a person might find they are suddenly denied access to their “money” because they became a person who was no longer authorized to use their card.
And we have God’s promise this is some time in the future. Happily it is a system that cannot last long.
Hmmmmm, Let's see (for it is the number of a man.)...
6+6+6 = 18, 1+8 = 9
How many numbers in YOUR SSN?
BTW, try to go get a bank account, credit card, or job without your number...