Matthew 24:31-35

Mat 24:31 (KJB)
And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.

Then when the Lord returns he will dispatch His angels to all quadrants of the world and will at that time bring all His redeemed children or Elect to glory. This is also known as the rapture which takes place on the last day simultaneous with Judgment day for the unbelievers. (1 Cor 15:52 KJV) In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed. 1 Corinthians 15:52 confirms that the rapture of all the believers will be on the last day, at the last trump. Then at that moment, the believers will receive their glorified resurrected bodies. (1 Cor 15:53-54 KJV) For this corruptible must put on incorruption, and this mortal must put on immortality. {54} So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory.

Mat 24:32 (KJB)
Now learn a parable of the fig tree; When his branch is yet tender, and putteth forth leaves, ye know that summer is nigh:

Jesus uses a parable about a fig tree. When the fig tree buds and the leaves begin to appear, that is a sign the winter is over and springtime is here and summer will soon arrive. The branch is tender because the sap has congealed inside it during the winter. Something that congeals is something which goes from a liquid state to a solid state. This happens in the cheese industry during production.

Mat 24:33 (KJB)
So likewise ye, when ye shall see all these things, know that it is near, even at the doors.

Here Jesus sums up what He has been telling them in the way of signs of both events, the destruction of Jerusalem and His return to earth on the last day. Notice the word “doors” that it is plural. He is telling the disciples that when they see the signs of the approaching armies on Jerusalem then the desolation is right at the door. Then in the latter days, when the Christians see the signs in the earth and heavens, then He is at the door of His second coming. So two doors are in view because they are two separate events.

Mat 24:34 (KJB)
Verily I say unto you, This generation shall not pass, till all these things be fulfilled.

Here Jesus reverts back to the warning about the destruction of Jerusalem. The generation that He is speaking of is the one that will be present in Jerusalem in 70 A.D. This is certain because He uses two demonstrative pronouns, “this” which is singular and “these” which is plural. When these words are used, it is speaking of something that is near and not distant. The demonstrative pronoun represents something that is either near or distant. If Jesus was speaking of His return, He would have used the words “that” and “those.”

Mat 24:35 (KJB)
Heaven and earth shall pass away, but my words shall not pass away.

The words of Jesus are eternal and enduring and therefore will outlast the heavens and the earth. What is also in view here is the fact that what Jesus was warning them about, the coming destruction of Jerusalem is a sure thing and it will happen. Even if the earth and heavens pass away, what He said will not pass away because all will come to pass and that will include the second coming of Christ. What also must be factored in are two other things which Christ spoke about and that is the final abode of the unbelievers which is hell and the final abode of the believers which will be the New Heavens and the New Earth.