"These are the two olive trees, and the two candlesticks standing before the God of the earth." Revelation 11: 4
This is a reference to Zechariah 4: 2-3
"And said unto me, What seest thou? And I said, I have looked, and behold a candlestick all of gold, with a bowl upon the top of it, and his seven lamps thereon, and seven pipes to the seven lamps, which are upon the top thereof:
3. And two olive trees by it, one upon the right side of the bowl, and the other upon the left side thereof." Zechariah 4: 2-3
Ezra 3: 3 and 3: 8 explain that Jeshua and Zerubbabel were important in the rebuilding of the Wall and Temple at Jerusalem.
"Then stood up Jeshua the son of Jozadak, and his brethren the priests, and Zerubbabel the son of Shealtiel, and his brethren, and builded the altar of the God of Israel, to offer burnt offerings thereon, as it is written in the law of Moses the man of God." Ezra 3: 3
"Now in the second year of their coming unto the house of God at Jerusalem, in the second month, began Zerubbabel the son of Shealtiel, and Jeshua the son of Jozadak, and the remnant of their brethren the priests and the Levites, and all they that were come out of the captivity unto Jerusalem; and appointed the Levites, from twenty years old and upward, to set forward the work of the house of the LORD." Ezra 3: 8
The first part of Revelation 11 is a kind of very short history of the Body of Christ. Jeshua and Zerubbabel, the two leaders in the rebuilding of Jerusalem, represent the restoration of Israel and its transformation in Christ - who can be seen metaphorically as olive trees, and the oil of grace as the truth.
"And when they shall have finished their testimony, the beast that ascendeth out of the bottomless pit shall make war against them, and shall overcome them, and kill them. 8. And their dead bodies shall lie in the street of the great city, which spiritually is called Sodom and Egypt, where also our Lord was crucified............And after three days and an half the Spirit of life from God entered into them, and they stood upon their feet; and great fear fell upon them which saw them."
Even John Gill (1697-1771) in his commentary on Revelation 11 did not believe the Two Witnesses were literally two men. He says "And I will give power unto my two witnesses,.... By whom are meant, not Enoch and Elias, as some of the ancient fathers thought...........but these witnesses intend the ministers of the Gospel and churches of Christ, who have bore testimony for Christ, and against antichrist, ever since he appeared in the world; "
I would have to add that the Two Witnesses not only represent the ministers of the Gospel but also all the elect of Christ who are viewed in this chapter.
Nor did John Gill, writing before Christian Zionism began in the 19th century, think that the beast who comes up out of the bottomless pit literally kills the Two Witnesses. He says "And kill them; not corporeally, but civilly; for as their dead bodies lying three days and a half, that is, three years and a half, unburied, and their resurrection from the dead, and ascension to heaven, cannot be understood literally............they will be silenced; they will be banished, or removed into corners."
The Two Witnesses, representing, as Gill says, many ministers of the Gospel of Christ, are "killed" by the beast who comes up out of the bottomless pit. Gill says this beast is the "Romish antichrist," but he is the same entity seen in Revelation 9: 1-2, 11, the angel of the bottomless pit, a fallen angel or demon, called Abaddon and Apollyon. Since fallen angels do not run around literally killing people, this is a clue that the killing is metaphor. The beast or angel of the bottomless pit inspires the huge number of false prophets seen in Matthew 24: 11 and II Peter 2: 1-3 to "kill" the spiritual life in the Two Witnesses.
The Two Witnesses, after they are spiritually "killed" by the false prophets inspired by the beast of the bottomless pit are given spiritual life by the Spirit of God in Revelation 11: 11.