Let me try to explain. The government of that time will say that you must publicly affirm your association with the beast to receive an identifier. The placement of the identifier on your hand or forehead will itself be positioned as a continual affirmation of your association with Team Beast. So, if you are wearing it then you are proclaiming your association with the beast. The beast is described as hating God and hating Christians and persecuting them. If you wear its badge (mark), then you would be affirming those actions.

This, obviously, creates a problem for Christians who are commanded to love God and to love others.

If it was just an identifier that held no other meaning, then it's fine, but it's called the "mark of the beast" and it's described as a literal badge of association with this creature. It's not just a bank account number.

Hope that helps. If not, just imagine how odious it would be, especially to Democrats, if Republicans made it a requirement to wear your MAGA hat to buy food.