I always thought the Mark of the Beast, which is described in Revelation 13 as a mark put on hand or forehead of those who follow the Antichrist, would irrevocably damn any person who received it. So when the Left Behind series said a person could repent of it I thought that was heresy. Then I heard in the summer of 2012 of a Christian teacher who said the same thing and wrote a blog post suggesting he must be a heretic too.
Now it looks like I should apologize for that as repentance from the Mark is taught by two Christian teachers I think highly of:
First, John MacArthur
whose position is that no sin is unforgiveable if it is repented of.
Then, Chris Pinto who goes back to the Reformers, showing that they identified the Mark as connected with the Roman Catholic rite of Confirmation, which was said to implant an indelible mark on the confirmed person. If that is the identity of the Mark, then obviously one can repent of it or nobody could ever be saved out of the RCC. Pinto discussed the Mark in some recent radio shows:
http://www.noiseofthunder.com/storage/NOTR_MARK.GOSPEL.REVELATION_10.17.13.mp3 Mark's Ending and the Mark of the Beast, October 17
The Mark of the Beast, Part 2, October 19
History of the Mark of the Beast, October 25
Repentance From the Mark of the Beast, October 25
Seeking God again
11 months ago