One of the great issues of interpretation in Revelation is the identity of the two witnesses in chapter 11. Whoever they are, they have divine authority: they "prophesy" 1260 days in sackcloth (Rev. 11:3). Scripture also calls them the two prophets (verse 10). They deliver the prophetic message that John is required to "prophesy again" (Rev. 10:11).
In the Jewish legal system something had to be established by at least two witnesses in order to be accepted as true (Deut. 19:15). It was a good system because the two witnesses had to describe the incident separately in ways that agreed with each other. The court would not take it seriously if only one person said that so-and-so did it. The infamous O. J. Simpson trial was frustrating in that nothing could be established beyond a reasonable doubt since there were no witnesses. So the image of two witnesses suggests that the message is both serious and true (Rev. 11:3).
Who are these witnesses? Scripture depicts them as olive trees and as the lampstands of the sanctuary (verse 4). The description reminds us of the time of Zerubbabel, when the Jews were restoring the Temple after the exile to Babylon (Zech. 4). So the two witness are symbols of the power of the Holy Spirit to enlighten the earth through God's Word and His people. John further portrays the witnesses in terms of Moses and Elijah (Rev. 11:5, 6), who represented God despite great opposition. Although they suffer for the message, they are not powerless.
Students of Revelation through the centuries have offered two main explanations of who the witnesses are. The first is that they represent the Bible, the Old and New Testament (also reflecting the law [Moses] and prophets [Elijah] of the Jewish cannon). The Old Testament scriptures bear witness to Jesus (see John 5:39, 40; 19:35, 37). So the concept of two witnesses to Jesus could be a reference to the Scriptures.
Equal evidence exists for a second concept. The presence of Temple imagery points to the church, often referred to as the temple of God in the New Testament (1 Cor. 3:17; 1 Peter 2:1-10). The church on earth is the light of the world (Matt. 5:14-16), because witnessing is the church's primary task (Luke 24:48; Acts 1:8).
In Revelation Jesus is both the faithful witness (Rev. 1:5) and the Word of God (Rev. 19:13). So the options are two sides of the same coin. Either way the point of the passage is the power of God's end-time message to change the world in spite of great opposition.
Lord, help me to keep my eye focused on the mission You have given Your church. Help me to use Your Word to make a difference in my world today.