That is your opinion. Grammatically, it can go either way, and it is my opinion to read it the other way.
What "other way"?
21For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.
22And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened.
23Then (at that time) if any man shall say unto you, Lo, here is Christ, or there; believe it not.
24For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.
25Behold, I have told you before
Here is the elect for whom the great tribulation is cut short, followed by the rising of the antichrist, false prophet, false miracles:
Church:
10And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
11And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
12Therefore rejoice, ye heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.
ISRAEL:
13And when the dragon saw that he was cast unto the earth, he persecuted the woman which brought forth the man child.
14And to the woman were given two wings of a great eagle, that she might fly into the wilderness, into her place,
where she is nourished for a time, and times, and half a time, from the face of the serpent.
15And the serpent cast out of his mouth water as a flood after the woman, that he might cause her to be carried away of the flood.
16And the earth helped the woman, and the earth opened her mouth, and swallowed up the flood which the dragon cast out of his mouth.
Antichrist:
5And there was given unto him a mouth speaking great things and blasphemies; and
power was given unto him to continue forty and two months.
6And he opened his mouth in blasphemy against God, to blaspheme his name, and his tabernacle,
and them that dwell in heaven.
Again, here is the elect, prior to the revealing of the antichrist:
Revelation 7
Israel:
1And after these things I saw four angels standing on the four corners of the earth, holding the four winds of the earth, that the wind should not blow on the earth, nor on the sea, nor on any tree.
2And I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea,
3Saying, Hurt not the earth, neither the sea, nor the trees, till we have sealed the servants of our God in their foreheads.
4And I heard the number of them which were sealed: and there were sealed an hundred and forty and four thousand of all the tribes of the children of Israel.
5Of the tribe of Juda were sealed twelve thousand. Of the tribe of Reuben were sealed twelve thousand. Of the tribe of Gad were sealed twelve thousand.
6Of the tribe of Aser were sealed twelve thousand. Of the tribe of Nephthalim were sealed twelve thousand. Of the tribe of Manasses were sealed twelve thousand.
7Of the tribe of Simeon were sealed twelve thousand. Of the tribe of Levi were sealed twelve thousand. Of the tribe of Issachar were sealed twelve thousand.
8Of the tribe of Zabulon were sealed twelve thousand. Of the tribe of Joseph were sealed twelve thousand. Of the tribe of Benjamin were sealed twelve thousand.
9After this I beheld, an
Church:
d, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;
10And cried with a loud voice, saying, Salvation to our God which sitteth upon the throne, and unto the Lamb.
11And all the angels stood round about the throne, and about the elders and the four beasts, and fell before the throne on their faces, and worshipped God,
12Saying, Amen: Blessing, and glory, and wisdom, and thanksgiving, and honour, and power, and might, be unto our God for ever and ever. Amen.
13And one of the elders answered, saying unto me, What are these which are arrayed in white robes? and whence came they?
14And I said unto him, Sir, thou knowest. And he said to me,
These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb.
Antichrist:
Revelation 9
1And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit.
2And he opened the bottomless pit; and there arose a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit.
3And there came out of the smoke locusts upon the earth: and unto them was given power, as the scorpions of the earth have power.
4And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree; but only those men which have not the seal of God in their foreheads.
