Answer
The Bible mentions that some end-times events will occur in a temple in Jerusalem (Daniel 9:27; Matthew 24:15). Second Thessalonians 2:4, speaking of the Antichrist, tells us, "He will oppose and will exalt himself over everything that is called God or is worshiped, so that he sets himself up in God’s temple, proclaiming himself to be God." Before the end times can occur, a temple must be present for these events to occur in.
There is still the “small” problem of the Islamic Dome of the Rock being on the site where the Jewish temple is supposed to be. Muslims believe this is the place from which Mohammed ascended into heaven, making it the third most sacred of Muslim shrines. For the Jews to take over this place and build a temple upon it would be unthinkable in today’s political climate. But during the tribulation, the building of the Temple will come about, protected by the Antichrist (Daniel 9:24-27).
When we see the Temple being constructed, we can be sure the end times are indeed upon us. The Antichrist will be reigning, the Church will already have been raptured, and the first half of the tribulation will have passed. But there will still be time for people to come to Christ for salvation.