Where’s The Sudden Event?

Q

I’m confused about the Day of the Lord. In an answer to one of my questions you said that the Day of the Lord is the Great Tribulation. But 1 Thess.5:2,3 says that “the day of the Lord so comes as a thief in the night” and brings sudden destruction upon all those who are saying “Peace and safety;” at the day of the Lord’s onset. If it is the whole world that is saying peace and safety and the day of the Lord starts with the beginning of the Great Tribulation, then what event at the beginning of the Great Tribulation brings on this sudden destruction?

The devil’s initial wrath is focused against Israel and Christians. The first vial (bowl) judgment is a foul and loathsome sore. Also, at this time, all those that dwell on the earth are rejoicing, making merry and sending gifts one to another because the two witnesses are dead. I don’t see an event at the beginning of the Great Tribulation that would bring sudden destruction on those saying peace and safety, which seems to be a qualification for the start of the day of the Lord, according to 1Thess.5:2,3. What am I missing?

A

What I said is that the phrase “day of the Lord” is used for everything from the entire church age to the actual day of the Lord’s return, but is most often used in reference to the Great Tribulation. 1 Thes.5 :3 doesn’t say “the whole world” it just says “people”. But if the Day of the Lord doesn’t begin suddenly, why did the Lord warn the Jews in Israel to flee for the mountains on the very day the anti-Christ stands in the Temple, not even stopping for their coats? And to pray that nothing would prevent them from leaving, like winter or the Sabbath Day? (Matt. 24:15-21) The first event of the Great Tribulation is so sudden that the Lord himself has to rescue the fleeing Jews as if from a flash flood. (Rev. 12: 13-17)