From my understanding, anybody who receives the Mark of the Beast is eternally damned. What if they are forced to get a chip or tattoo without any say or will?
Also, I’ve always wondered what would happen if somebody is to receive the Mark of the Beast, but then repent later. Are they born again or is it too late for them and they’re damned?
Your understanding is correct. Rev. 14:9-13 clearly states that anyone who worships the beast or takes his mark will be irretrievably lost. There will be no opportunity to repent. Believers will be expected to resist to the point of death. Their resurrection is mentioned in Rev. 20:4