Summary: The temple that John is measuring is the church of Jesus Christ, and both it and its voice, the witnesses, will complete their mission.
This is the hardest chapter in the entire book of Revelation to interpret. At least that’s what all my commentators say. And that’s about the only thing they can all agree on. So I hope I don’t leave you all more confused than you were before we began.
The first thing to remember is where we are in the whole grand sweep of the book. Remember that we’ve seen Jesus enthroned as the Risen Lamb and recognized as the only one qualified to open the scroll with the seven seals which contains God’s entire plan for human salvation. All seven of the seals have been opened. Famine and plagues and wars and natural disasters - or should I say acts of God? earthquakes and floods and volcanoes - they’ve all been let loose on the earth. We’re nearing the end of the events set in motion by the opening of the seventh seal. Six angels have sounded their trumpets, each one bringing more destruction. The seventh angel tells John to quit writing, to eat the scroll - that is, fill himself with the word of God - and to go back and tell the world what God is doing. And then, as often happens in dreams - and remember this whole book is a dream, a vision - the scene shifts to a new location. So now in chapter 11 we’re still in that intermission between the sixth and seventh trumpets when the action is taking place down at our level rather than in God’s throne room, and John has changed roles. He’s no longer an observer, he’s an actor in God’s heavenly drama.
As the scene opens, John is given a measuring rod, a yardstick, and told "Come and measure the temple of God and the altar and those who worship there.” [v. 1] And now comes the hard part. What is the temple? What is it that John is supposed to measure? And does he mean measure, as in size or number, or measure as in assess and evaluate?
First of all, whether John is to pace out the area or check the condition of the roof, the act of measuring by itself is a claim of ownership by God. It’s the first step you take before you sell or remodel or move into your property. Before the builders - or the movers - show up you have to get an appraisal.
But that still leaves us with the larger problem. What is this temple? It is clear that it’s an earthly one, not the heavenly temple we saw back in chapter 7. But even the heavenly temple - and the copy Moses made of it in the tabernacle in the wilderness - are symbolic. They are attempts to convey the nature of God’s dwelling place. Even Solomon, when he built the first temple in Jerusalem, knew that any building necessarily had to be symbolic, because he says: "But will God indeed dwell on the earth? Even heaven and the highest heaven cannot contain you, much less this house that I have built! ' [1 Ki 8:27]
Some people do believe that a fourth temple has to be rebuilt in Jerusalem right here the original one stood. But the last one was destroyed in 70 A. D when Titus, the son of the Roman Emperor Vespasian, laid siege to the city. The defenders were absolutely committed to holding their ground; the Jewish historian Josephus reported that some of the people in the city actually ate their own children in order to keep themselves alive and the Romans out just a little while longer, but eventually the Romans broke through and completely demolished the temple, just as Jesus had predicted. He told the disciples, “Truly I tell you, not one stone will be left here upon another; all will be thrown down." [Mt 24:2] All that is left today is a bit of the Western Wall, more commonly known as the wailing wall, where observant Jews weep and pray.