Even Jesus did not know the day and hour of the second advent. He said that only the FATHER knows. Theories are OK as long as we do not make them doctrine. Christ returns early to stop the tribulation else no one would be left alive. The two witnesses, after being killed, are resurrected 3 1/2 days later and rise up into the air to meet the returning Jesus. I would think that at that time , when they are killed, we, if alive, will know that in 3 1/2 days Jesus returns. When the antichrist signs a covenant with 10 nations this begins the countdown of the final “week” and at the midpoint of that week 1260 days into it, antichrist defiles the temple, as Paul said, declaring himself GOD. This event is the beginning of the great tribulation that is cut short for the sake of the elect, who are the church, and this indicates the church is still on Earth at the time of the great tribulation but is protected from this hour of trial that comes upon the whole earth. Revelation 3:10 Jesus was only involved with the earth twice, during his fleshy existence and second when he returns in glory. Hebrews 9:28 verifies this. Also in his prayer to the FATHER in John 17:5 Jesus specifically asked his FATHER to not take the church out of the world. The rapture theory began in 1830 by a Scottish woman , Margaret Macdonald, it was then popularized by a preacher, John Nelson Darby. If Christ re in secret before the tribulation this would be his third interaction with the earth when Hebrews 9:28 limits his appearances to only two times, his life on earth and the second advent. The confusion seems to come from making how we meet Jesus in the air with the second advent, making two separate occurrences rather than just one. The church rises up to meet the Christ at his return, not at some time beforehand. Certain scriptures are misused and misinterpreted to develop this rapture theory. This Macdonald woman and false preacher Darby literally invented the rapture from their own carnal minds.