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Since I have noticed that people who have no interest in hearing about the prophesies of the 3 days of darkness are generally either those who have no interest in religion or else they're very hostile toward the Catholic Faith (there are exceptions but not many), I suppose what you're saying makes sense, that it would have the purpose of destroying the enemies of the Church, since they'll be the ones who will not heed the warnings not to go outside, not to look out the window, but to have blessed candles on hand and to be careful in your storage of water and food, as described in this video. People who think this is all propaganda or whatever will simply die.
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