Well it's probably pretty hard to barter if they take one look at you and see that you haven't you know taken the mark. At that point you don't even have to have a currency technically speaking, they at best won't affiliate with you because it will be obvious you're not one of them, or at the worst I mean, they might kill you, but I mean you know, like the world ends shortly after and you get resurrected anyways by God so like not really a big deal if you believe in Jesus.