There are several questions here, but that's OK
Because (1) God knows who did not reject the Gospel and reject Christ before the Rapture and (2) He is ever merciful.
The two witnesses will be seen worldwide and so will the angel who has the everlasting Gospel.
Why not? There was only one witness at the time of Noah, and that was Noah.
Using the communication technology which surrounds us.
God's wrath will be against unbelief and ungodliness, as well as against the worldwide idolatry perpetrated by the Antichrist.
Before the New Heavens and the New Earth come into existence, God must deal with His enemies and cleanse the earth from all those who oppose Him and reject Christ. The ultimate objective is to establish the universal Kingdom of God on earth.
The mark of the Beast seals individuals for Hell. It is for those (a) who believed not the truth when they heard it and (2) who were placed under strong delusion in order to believe the lies of Satan. What we seem to forget is that the Gospel is being preached throughout the world (and must be before the Second Coming of Christ). Many are being saved, but many more are scoffing, or rejecting Christ, or going after false gods. Those who desire false gods will receive them. Muslims as well as Hindus and others have become more and more radicalized. Many Jews continue to reject Jesus. Atheists and sexual perverts have become more vocal, and promote their agendas more strongly than before. Gnosticism has been revived, as has witchcraft and occultism in the West. And one could add many more developments to this list. All of these factors are leading to the reign of the Antichrist.
I don't know how to box the quotes so I numbered my questions and put You and Me where each of us replied.
1. If we are taken out of here before the great tribulation then why would God give anyone else a chance to repent?
You: Because (1) God knows who did not reject the Gospel and reject Christ before the Rapture and (2) He is ever merciful.
Me: That did not answer the question. When we are taken up the dead in Christ rise from their grave first and join those who are still alive then we are taken up to the clouds to meet Jesus in the air and we will be with the Lord forever. 1Thessalonians 4:17 never says we will be with the Lord in Heaven, but only in the air as we come back with Him as part of His army in Rev 19 as we are the ones who are clothed in fine linen, white and clean.
2.How would they hear if the gospel was no longer preached in the world.
You:The two witnesses will be seen worldwide and so will the angel who has the everlasting Gospel.
Me: How can only two witness be seen worldwide as that would be impossible. Zechariah 4:1-6; 4:11-14 explains that these two witnesses are the word of God in all power and might and the Holy Spirit which is the oil that is poured out on those who God anoints with His Holy Spirit, Joel 2:28-32; Acts 2:17-21. According to those scriptures I gave here the Church is still here at that time as we are the witnesses Rev Chapter 11 speaks about.
3. Do you really think God would take us up, but to only leave two witnesses behind?
You: Why not? There was only one witness at the time of Noah, and that was Noah.
Me: Did God take Noah up to be with Him in Heaven at the time of the flood, no, as it repented God that he made man for their hearts turned evil, but found favor in Noah only, Genesis 6:6. so it only comes to figure Noah would be a witness until the time of his death.
4. How are only two witnesses going to preach to all the nations in the world?
You: Using the communication technology which surrounds us.
Me: Many remote places around the world have no technology so that's not going to work out.
5. If we are taken up before the tribulation then what would be the whole purpose of seven years of Gods wrath?
You: God's wrath will be against unbelief and ungodliness, as well as against the worldwide idolatry perpetrated by the Antichrist.
Me: We all know what Gods wrath is all about and do you really think it would take God seven years to rid the world of all its evil. All God has to do is speak it all to be gone and it would be finished.
6. Would God not just end everything at that time?
You: Before the New Heavens and the New Earth come into existence, God must deal with His enemies and cleanse the earth from all those who oppose Him and reject Christ. The ultimate objective is to establish the universal Kingdom of God on earth.
Me: And you think it will really take God seven years or better to do all that since we are no longer suppose to be here.
7. What about the mark of the beast? What purpose would that be if we are all gone? Just some things to think about.
You: The mark of the Beast seals individuals for Hell. It is for those (a) who believed not the truth when they heard it and (2) who were placed under strong delusion in order to believe the lies of Satan. What we seem to forget is that the Gospel is being preached throughout the world (and must be before the Second Coming of Christ). Many are being saved, but many more are scoffing, or rejecting Christ, or going after false gods. Those who desire false gods will receive them. Muslims as well as Hindus and others have become more and more radicalized. Many Jews continue to reject Jesus. Atheists and sexual perverts have become more vocal, and promote their agendas more strongly than before. Gnosticism has been revived, as has witchcraft and occultism in the West. And one could add many more developments to this list. All of these factors are leading to the reign of the Antichrist.
Me: Those who have rejected the witness of Christ are already condemned if they refuse to repent, John 3:18, so they would not need a mark from the beast to show that as they live their life by that of following after the beast. Mat 24:13 But he that shall endure unto the end, the same shall be saved. Mat 24:14 And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come. The Gospel of the kingdom is preached throughout the world by those who have been anointed to preach it as we are still here on earth and only God knows the last one that will repent and then the end comes. The end does not come until Jesus plants His feet on the Mount of Olives and brings His army who have now been caught up to the clouds to meet Jesus in the air and come back with Him, Rev 19, to fight the final battle as the beast and false prophet will be cast into the lake of fire at that time. There is no one Antichrist for scripture say there are many, 1John 2:18,22; 4:3; 2John 1:7. No where in scripture does it speak about just one Antichrist, but says spirit of antichrist in the particular of those who reject Jesus.