Possible explanation
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Not all Christians believe in the rapture and many have different interpretations on whether it's pre, mid, or post tribulational
However, most people I've encountered seem to believe that it's a miraculous event where all those accepted into God's kingdom will be transported in the blink of an eye, and that millions of people will literally disappear.
However, it's highly possible that this event in the scripture is misinterpreted to at least some extent.
I believe that the rapture does take place, but it's possible that it is not a miraculous event, but rather, the largest mass murder to ever be conducted in history.
What does the Yeshua say in the book of Luke, chapter 17..
34 I tell you, on that night two people will be in one bed; one will be taken and the other left.
35 Two women will be grinding grain together; one will be taken and the other left.
37 “Where, Lord?” they asked.
He replied, “Where there is a dead body, there the vultures will gather.”
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Throughout history for this to happen it would have had to be a miraculous event since millions are effected instantaneously, thus it's always been taught that way, but today..
It's possible with microchips and highly sophisticated electronic weapons that the rapture is actually the mass killing of Gods people, that literally takes place in a very short time period.
It's possible after this mass killing that the new religion will be implemented and those that refuse the mark of the beast will be beheaded like the Bible says in Revelation.
Yeshua also says,
"when the son of man returns, will he find faith on the earth"
His words imply that there will be little to none.
So it's possible that this event will spawn some amount of new believers of those who manage to escape the guillotine and live off grid.
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This scenario would explain how taking the mark of the beast leads to damnation since Yeshua says that the only sin that won't be forgiven is blasphemy of the holy Spirit, which I believe is rejecting God's ways to the very end.
Therefore, the people taking the mark, would only be those who are willing to embrace evil for the rest of their days.
This may even entail operating the guillotine to end the life of one who doesn't take the mark to show your loyalty.
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For those that believe Christ's return shortly after the rapture, this would also explain the confusion of why Yeshua calls the chosen up only to bring them right back.