So many out there seem to be endlessly searching for what will be "The Mark of the Beast" falling into the trap of looking for a literal meaning when the bible is mostly metaphorical. Its my belief which Im sure isnt a new concept it simply means that you cling to the desires of the flesh rather than to the things of the spirit. The mark on your hands would be your actions and the mark on your forehead would be your thoughts. The Bible says in Revelation 13:18 that 666 is "the number of a man" (or "the number of the beast"). meaning do you cling to the things of this world or to those of the spirit.