The (Two Witnesses) are literally prophets returned, they represent the altar of God upon earth, you will note in Revelation chapter 5 the "Golden Oil" represents the prayers of the saints, the two witnesses will literally pour this golden oil through themselves upon the wicked in "Plagues" a remake of Moses/Aaron against Pharaoh of Egypt
Revelation chapter 11 clearly teaches that the two witnesses will have literal bodies that die, lay in a literal street in Jerusalem, and be literally raised to heaven, before a literal world watching
Revelation 5:8KJV
8 And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints.
Zechariah 4:11-14KJV
11 Then answered I, and said unto him, What are these two olive trees upon the right side of the candlestick and upon the left side thereof?
12 And I answered again, and said unto him, What be these two olive branches which through the two golden pipes empty the golden oil out of themselves?
13 And he answered me and said, Knowest thou not what these be? And I said, No, my lord.
14 Then said he, These are the two anointed ones, that stand by the Lord of the whole earth.