Revelation 13

Here is wisdom. Let him who has understanding calculate the number of the beast, for it is the number of a man: His number is 666. v.18

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666 Everyone knows that means Satan whether one's ever read the Bible or not. And here it is in Revelation chapter thirteen. Now why is this number associated with Satan? It says here that if you calculate the number of the beast, meaning the letters of his name, it equals 666. In Greek it is the three letters CH, X, S which numerical value is 666, which is his name. We don't know what his name will be yet at this future time. It also says this number is the number of a man, meaning that this beast is just a man and not God.
This number is possibly the mark of the beast we read about in verse sixteen and those that don't have it can neither buy nor sell during this time. Those that are following God during this tribulation time that don't get the mark doesn't mean they're starving because they cant buy or sell, because the Kingdom system does not have commerce like we do today. Satan has tried to instate commerce again, yet those that don't get the mark already know how to live without this commerce as they have done for the duration of the kingdom thus far before this point in time. Those that get the mark of the beast wont be tricked into it like how people get tricked into getting a credit card today, but this will be purposeful of those who get the mark of the beast as to choosing to join this false religion.
The number seven in scripture shows perfection. Six is less than seven, as Satan falls short of perfection, falls short of God, which has been his aim to be God since Genesis 1.
This number is not some superstitious thing that if you have 666 stairs in your church building that this is actually of the devil.
May we as easily that recognize this number of Satan just as easily recognize his scheming and continue to follow Christ who is True and Perfect!