1. there is no mention of "rapture" 1 Thessalonians 4:16 very clearly is talking of those who died before Christ -
13 But I would not have you to be ignorant, brethren, concerning those who are asleep, that ye sorrow not, even as others who have no hope.Rev 4:1 is about John seeing in his vision.
14 For if we believe that Jesus died and rose again, even so will God bring with Him those also who sleep in Jesus.
15 For this we say unto you by the Word of the Lord: that we who are alive and remain unto the coming of the Lord, shall not precede those who are asleep.
16 For the Lord Himself shall descend from Heaven with a shout, with the voice of the archangel and with the trumpet of God; and the dead in Christ shall rise first;
17 then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And so shall we ever be with the Lord.
18 Therefore comfort one another with these words.
Jesus HAS resurrected. He went down to the dead and opened the gates of heaven for all - including those asleep
it wasn't in the Bible in the sense you use it in - not even in the Vulgate
The Tribulation period is clearly as you read from REv 1 when John who shares in the reads tribulations talks of the Nero based persecutions of the Church, just at the same time that Sadducee and Pharisee persecution of the Christ-follower sect (yes, the Christians were still a sect of 2nd temple Judaism along with the Pharisee sect) was also peaking