The two witnesses are resurrected and lifted up to heaven after completing their testimony. How is this different from the rapture of the saints with the second coming of Christ?
As I explained with my answer for Q. 2, these two witnesses are God's special servants whom He would raise from the people of Israel to save the Israelites. There is an important work that God must do before destroying this world, and that is to save the people of Israel from sin and make them participate in the first resurrection and the rapture.
The Apostle Paul said in Romans 3:29-30, "Or is He the God of
the Jews only? Is He not also the God of the Gentiles? Yes, of the
Gentiles also, since there is one God who will justify the circumcised
by faith and the uncircumcised through faith." The way to be
saved from sin before God is the same for both the Jews and the
Gentiles. For both the Jews and the Gentiles alike, justification
comes only through their faith in the gospel of the water and the
Spirit. To be saved from all their sins, the Jewish people must
also accept Jesus Christ as their Savior and believe, just as the
Gentiles believe, that Jesus Christ took all their sins upon Himself
with His baptism, and that He died on the Cross to be judged of
these sins on their behalf.
God treats both the Jews and the Gentiles alike, and has permitted both of them the same salvation through faith. This is why God allowed His two witnesses to the Jewish people during the time of the first three and a half years of the Great Tribulation, and why He allowed these witnesses to preach the gospel of the water and the Spirit to them.
In connection with these two witnesses, chapter 11 of Revelation refers to the two olive trees and the two lampstands. The two olive trees refer to these two servants of God whom He would allow for the salvation of the Israelites, and the two lampstands refer to God's two Churches, which are of the Israelites and of the Gentiles. God would allow, in other words, His two Churches alongside each other to preach the gospel of the water and the Spirit to the Israelites and the Gentiles during the first three and a half years of the Great Tribulation.
Right now, God's Church is not found among the Israelites. But when God searches their hearts and when His time comes, He will prepare their hearts to receive His Word, raise the two servants for them, and make them accept Jesus Christ as their Savior.
God therefore will save both the Israelites and the Gentiles during the time of the Great Tribulation. He will also allow the persecution and martyrdom of the born-again saints to both the Israelites and the Gentiles alike. The fact the two witnesses are martyred after completing their testimony and then are resurrected and lifted up to heaven in three and a half days-this ultimately contains the fact that just like these two witnesses, the servants of God and His people among the Gentiles would also fight against the Antichrist, be martyred, and thereby participate in their resurrection and rapture.