On the “mark” issue, it’s pretty clear that NO ONE can buy or sell without it, in any manner whatsoever.
This would require an absolutely intrusive surveillance state that is starting to come to fruition.
I do believe we’re in the season of the Lord’s Return.
Who NEEDS to when the gummint will supply your food (show up at a school), your medicine, your entertainment and your lodging. (Lots of 'homeless' being enabled by do-gooders.)