A recent thought concerning the rapture is that it is at the 6th seal in Rev 6:12-17. In connection to this some believe that the seals have already been opened through Church history and that the 6th seal is the next to be opened (with the rapture). I was recently asked why I don't agree with this and wrote the following 7 quick points from Revelation.
1. The God given outline/order for Revelation is in Rev 1:19 where John is told to write the past, present and future things. The present things, 'the things which are', speak of the 7 churches representing the church age. The future things, that which take place 'after these' ('meta tauta') starts in Rev 4:1 where this phrase 'meta tauta' is used twice in the one verse to make it clear this starts the future things. In other words the future events, after the church age, start in Rev 4:1, not in Rev 6:12 or thereabouts.
2. In connection to point 1, Rev 4:1 is a far greater pointer to the rapture than the 6th seal. The imagery used in Rev 4:1 has an open door to heaven (which only opens twice in Revelation, here and when Jesus returns in Rev 19:11), a trumpet sound, a command given by Jesus to 'come up here' and an instant translation of John immediately into Heaven before the throne. This is a type of the rapture at the end of the church age before the 'future things' begin. John was called to ‘come up here’ to see the things that take place ‘after this’ and so will the church. In comparison, the 6th seal doesn't have the key signs of the rapture that we would expect. There is no trumpet, no shout or command, no coming of the Lord mentioned or any sign of believers getting caught up into heaven at the 6th seal.
3. If the seals have been opened already and the rider on the white horse is the church right from Pentecost, when did they/we receive our 'stephanos' victors crown as this rider has? Believers in Christ do not receive their crowns until the judgement seat of Christ. Not before. Until then we run the race but it is not till the judgement seat, after the Lord returns, that we receive our rewards. Rev 22:12 Behold, I am coming soon! My reward is with me, and I will give to everyone according to what he has done.
4. In connection to 3 above the elders are seen with their 'stephanos' victor’s crown. So Jesus has come by this point (because the crowns aren't given till He returns) which makes sense as the cross-over point to 'future things' is Rev 4:1, not the end of chapter 6. To say that the elders are Old Testament saints taken to heaven after the resurrection ignores the fact that everything seen in the elders (seated on thrones, dressed in white, crowns of gold etc) are promises in the letters given to the Church (Rev 3:21, Rev 3:4, Rev 2:10). It also ignores the fact that Old Testament saints are NOT made perfect without us (Heb 11:40) so will not be rewarded with their crowns yet.
5. If the seals with the 4 horsemen have already been opened during the Church age then you have Jesus opening these seals and bringing forth judgements that include the death of 1/4 of the earth's population… during the age of grace! (Rev 6:8) It just doesn't make sense. Not only can we not point to when the seals have been opened in history (ie when did 1/4 of the earth’s population die?), but this is still the age of grace, not the day of vengeance and judgement.
6. Many Bible scholars have noted the connection (in order even) between the seals and the events leading up to the second coming as stated by Jesus in Matt 24. For example, speaking of the signs of His coming Jesus said there would be false Christs (1st seal, rider on white horse), wars and rumours of wars (2nd seal, war, peace taken from earth), famine, plagues and earthquakes (3rd seal famine, 4th seal death), martyrdom (5th seal martyrs), then later after the tribulation the heavenly signs announcing His coming (6th seal heavenly signs). These signs are end time birth pains and tribulation signs, as are the seals, not general things that happen throughout the 2000 year church age.
7. Finally, in connection to 6 and the mention of the 6th seal, let me go out on a wee limb and say that I believe the 6th seal is AT THE END of the tribulation, not the start as you have it. Jesus spoke of these exact signs in Matt 24:29 as AFTER the tribulation and linked it with His second coming (Matt 24:30) when all the nations see Him. Isaiah also spoke of this event (6th seal) when the heavens will be rolled up as a scroll (Isa 34:4) and linked it with the Lord’s destruction of the earth’s armies (Isa 34:2-3) and the great sacrifice even in Bozrah. This is when/where the Lord returns to at His 2nd coming to destroy those that try to kill the remnant of Israel hiding there (Isa 63:1-6). This is all second coming in glory stuff! And Isaiah places the 6th seal at this event at the end of the tribulation. As did Jesus Himself.
I realise this last point differs from the more traditional view that the seals lead on into the trumpets. I believe that the seals give an overview of the entire tribulation period leading right to the end. I have written a little about this here if interested: https://jesusplusnothing.com/series/post/chronology-of-revelation
Hope this helps.