What is the 'Mark of the Antichrist'?



What type of figure is 'Antichrist'?  What doctrines of antichrist have been seen throughout the Church age?  What did the Apostle John teach to help us identify antichrists?  What does the 'mystery of lawlessness' have to do with any of this?  Could the time of Easter or Passover give clues?  What have Christians been persecuted for?  What does the Catholic call its 'mark'?  What do the Eastern Orthodox and Protestant teach?  What is planned for those who keep the Sabbath and will not wear crosses?

A written article of related interest is titled:  The Mark of Antichrist?