21:25-37 And there will be signs in sun, and moon, and stars, and on earth the nations will be in distress and will not know what to do in the roaring of the sea and of the wave, while men's hearts will swoon from fear and from foreboding of the things that are coming on the world. The power of the heavens will be shaken; and then they will see the Son of Man coming in a cloud, with power and much glory. When these things begin to happen, look up and lift up your hearts for your deliverance is near.
And he spoke this parable to them, "Look at the fig-tree and all the trees; whenever they put out their leaves, you see it for yourselves and you know that the harvest is near. So, whenever you see these things happening, you know that the kingdom of God is near. This is the truth I tell you, that this generation will not pass away until all these things have happened. The heaven and the earth will pass away, but my words will not pass away."
Take care lest your hearts grow heavy with dissipation and drunkenness and anxieties for the things of this life, and lest that day come suddenly upon you like a trap closing, for it will come upon all who dwell upon the face of the earth. Be watchful at all times, and keep praying that you may have strength to escape all the things that are going to happen, and to be able to stand before the Son of Man.
During the days Jesus was teaching in the Temple, but at night he went out and stayed in the Mount called the Mount of Olives; and all the people came early in the morning to listen to him in the Temple.
There are two main conceptions here.
(i) There is the conception of the second coming of Jesus Christ. There has always been much useless argument and speculation about the second coming. When it will be and what it will be like, are not ours to know. But the one great truth it enshrines is this--that history is going somewhere. The Stoics regarded history as circular. They held that every three thousand years or so the world was consumed by a great conflagration, then it started all over again and history repeated itself. That meant that history was going nowhere and men were tramping round on a kind of eternal treadmill. The Christian conception of history is that it has a goal and at that goal Jesus Christ will be Lord of all. That is all we know, and all we need to know.
(ii) There is stressed the need to be upon the watch. The Christian must never come to think that he is living in a settled situation. He must be a man who lives in a permanent state of expectation. A novelist, in one of her books, has a character who will not stoop to certain things that others do. "I know," she said, "that some day the great thing will come into my life and I want to keep myself fit to take it." We must live forever in the shadow of eternity, in the certainty that we are men who are fitting or unfitting themselves to appear in the presence of God. There can be nothing so thrilling as the Christian life.
(iii) Jesus spent the day amidst the crowds of the Temple; he spent the night beneath the stars with God. He won his strength to meet the crowds through his quiet time alone; he could face men because he came to men from God's presence.
-Barclay's Daily Study Bible (NT)