Did Jesus say that when he comes, it would be the end of the world? I don't think he did.
This and also by inference from other scriptures, Like Peter says in 2 Peter 3, we know it is the end of the world and the beginning of a new world.
Specifically though, Matthew 24
2 Peter 3, this is the Day Christ returns
The Day of the Lord
10 But the day of the Lord will come as a thief in the night, in which the heavens will pass away with a great noise, and the elements will melt with fervent heat; both the earth and the works that are in it will be [
d]burned up. 11 Therefore, since all these things will be dissolved, what manner
of persons ought you to be in holy conduct and godliness, 12 looking for and hastening the coming of the day of God, because of which the heavens will be dissolved, being on fire, and the elements will melt with fervent heat? 13 Nevertheless we, according to His promise, look for new heavens and a new earth in which righteousness dwells.
Hebrews 2:5
For unto the angels hath he not put in subjection the
world to come, whereof we speak.
Hebrews 6:5
And have tasted the good word of God, and the powers of the
world to come,
Hebrews 1
10 And:
“You, Lord, in the beginning laid the foundation of the earth,
And the heavens are the work of Your hands.
11 They will perish, but You remain;
And they will all grow old like a garment;
12 Like a cloak You will fold them up,
And they will be changed.
But You are the same,
And Your years will not fail.”
Revelation 6
Sixth Seal: Cosmic Disturbances
12 I looked when He opened the sixth seal, and [
g]behold, there was a great earthquake; and the sun became black as sackcloth of hair, and the [
h]moon became like blood. 13 And the stars of heaven fell to the earth, as a fig tree drops its late figs when it is shaken by a mighty wind. 14 Then the sky [
i]receded as a scroll when it is rolled up, and every mountain and island was moved out of its place. 15 And the kings of the earth, the great men, [
j]the rich men, the commanders, the mighty men, every slave and every free man, hid themselves in the caves and in the rocks of the mountains, 16 and said to the mountains and rocks, “Fall on us and hide us from the face of Him who sits on the throne and from the wrath of the Lamb! 17 For the great day of His wrath has come, and who is able to stand?”
Matthew 24
1 And Jesus went out, and departed from the temple: and his disciples came to him for to shew him the buildings of the temple.
2 And Jesus said unto them, See ye not all these things? verily I say unto you, There shall not be left here one stone upon another, that shall not be thrown down.
3 And as he sat upon the mount of Olives, the disciples came unto him privately, saying,
Tell us, when shall these things be? and what shall be the sign of thy coming, and of the end of the world?
4 And Jesus answered and said unto them, Take heed that no man deceive you.
5 For many shall come in my name, saying, I am Christ; and shall deceive many.
6 And ye shall hear of wars and rumours of wars: see that ye be not troubled: for all these things must come to pass,
but the end is not yet.
7 For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places.
8 All these are the beginning of sorrows.
9 Then shall they deliver you up to be afflicted, and shall kill you: and ye shall be hated of all nations for my name's sake.
10 And then shall many be offended, and shall betray one another, and shall hate one another.
11 And many false prophets shall rise, and shall deceive many.
12 And because iniquity shall abound, the love of many shall wax cold.
13 But he that shall endure unto the end, the same shall be saved.
14 And this gospel of the kingdom will be preached in all the world as a witness to all the nations, and
then the end will come.