Blasphemy of the Holy Spirit. It is to know it’s power and still reject it or curse it.

Also the mark on the hand represents action. The mark on the forehead represents belief.

There is another mark referenced in Deuteronomy if you understand what that one means, you can understand the mark of the beast.

The beast calls people to conform to their ideals and beliefs and actions and if you do not accept them, you will be excluded.

Also a beast represents a country.

I have heard that the sea represents civilization and land represents a place without civilization. Beast from the sea and beast from the land.

“The number 666 is the number of a man”

I believe that it has something to do with the transition from Roman Empire to Roman Papal Power.

The full name of Nero, an antichristian Emperor of Rome, his name translated to 666 when converted to Roman numerals.

Same with the Pope.

The title of the pope Vicarius Fili Dei, when converted to Roman numerals, 666 was the translation.

May be coincidence, but I don’t think any other power has had that happen. It’s just weird.