Mat 24:15 "Therefore when you see the abomination of desolation, spoken of by Daniel the prophet, standing in the holy place (whoever reads, let him understand),"
Abomination is Satan, Antichrist and whatever is abominable in the Bible.
Desolation is complete destruction of our faith in God, Jesus, His words, promises and teachings, etc.
So the abomination of desolation is the person/thing that will completely destroy our faith in God, His words, teachings, prophecies, promises, etc. and in our Lord Jesus Christ.
Dan 11:29-31 "At the appointed time he shall return and go toward the south; but it shall not be like the former or the latter. For ships from Western land (Cyprus) shall come against him; therefore he shall be grieved, and return in rage against the holy covenant, and do damage. "So he shall return and show regard for those who forsake the holy covenant. And forces shall be mustered by him, and they shall defile the sanctuary fortress; then they shall take away the daily sacrifices, and place there the abomination of desolation.
1. At the appointed time - the time fixed by God (esp. last days)
2. For ships from Western land (Cyprus) shall come against him - the original word means Western land (not Cyprus) or US and EU.
3. return in rage against the holy covenant, and do damage - persecute and kill Christians.
4 show regard for those who forsake the holy covenant - reward all deceived Christians who apostate.
5. they shall defile the sanctuary fortress - conquer Jerusalem.
6. they shall take away the daily sacrifices - stop or destroy the house of worship (mosque)
7. place there the abomination of desolation - replacing the mosque with the abominable house of worship to deceive Christians.
During WW3 the king of the North (Antichrist) with allies will defeat the West (Babylon). He will conquer Israel and Jerusalem. After the war he will deceive the Muslims to tear down the Al-Qusa mosque and 'Dome on the Rock'. In its place, the Antichrist will request the Jewish Priesthood to build the temple of God of the 'One World Religion' (for the Antichrist) or 'the abomination of desolation' spoken of by Daniel the prophet.
Mat 23:20-21 "Therefore he who swears by the altar, swears by it and by all things on it. He who swears by the temple, swears by it and by Him who dwells in it."
The temple of God is only a building and cannot destroy our faith. Our Lord advised us to beware of the satanic Antichrist dwelling in the temple to deceive Christians. So we can safely refer to the abomination of desolation as the Antichrist.
Mark 13:14 "So when you see the 'abomination of desolation,' spoken of by Daniel the prophet, standing where it ought not" (let the reader understand), "then let those who are in Judea flee to the mountains"
So when we see the Antichrist standing in the holy place where he is not supposed to be (where it ought not), then the Jews in Judea must flee to the mountains for the Great Tribulation has begun.
Note:- Kong Solomon dedicated the temple of God but the Antichrist (a Gentile) is not a Jewish king, so how can he be allowed to stand at the temple of God (holy place) sacrificing animals and dedicating the temple?
2Chron 5:6 Also King Solomon, and all the congregation of Israel who were assembled with him before the ark, were sacrificing sheep and oxen that could not be counted or numbered for multitude.