Here is what the true Torah Jews have to say about the Third Temple:
“At the same time, we wish to warn Jews that even if the Zionists do, G-d forbid, succeed in building a temple, it will not be the long-awaited Third Temple of G-d, but a temple of Satanic forces. This was stated 90 years ago by Rabbi Shmuel Weinberg, the Slonimer Rebbe, on his deathbed: “Jews, you must know that before the coming of the messiah, a group of unsavory people will travel to Eretz Yisroel, and they will enjoy great victories there, and they will build a temple, and a fire will come down from heaven in this temple as it did in the First Temple. And you must know that this fire will not be from the Holy Side, but from the Other Side.” (source)
What Paul warned about in 2 Thess. 2, a warning ignored by many ‘Christian’ Zionists, to our own peril — as they support evil:
Let no one deceive you in any way. For it will not be, unless the departure comes first, and the man of sin is revealed, the son of destruction, he who opposes and exalts himself against all that is called God or that is worshiped; so that he sits as God in the temple of God, setting himself up as God. Don’t you remember that, when I was still with you, I told you these things? Now you know what is restraining him, to the end that he may be revealed in his own season. For the mystery of lawlessness already works. Only there is one who restrains now, until he is taken out of the way. Then the lawless one will be revealed, whom the Lord will kill with the breath of his mouth, and destroy by the manifestation of his coming; even he whose coming is according to the working of Satan with all power and signs and lying wonders, and with all deception of wickedness for those who are being lost, because they didn’t receive the love of the truth, that they might be saved.