He taught them a lesson. "Consider the fig tree and all the other trees. When their buds burst open, you see for yourselves and know that summer is now near; in the same way, when you see these things happening, know that the kingdom of God is near. Amen, I say to you, this generation will not pass away until all these things have taken place. Heaven and earth will pass away, but my words will not pass away. (Lk 21:29-33)
Jesus makes use of parables and stories to communicate lessons about the kingdom of God. This time he picks up a fig tree to learn a lesson. Whatever happens in nature and in history are not mere happenings but they are lessons for life and particularly about the kingdom of God.
Destructions, desolations, wars, signs in the sky are all lessons about the kingdom. One important lesson is that the kingdom of God is at hand. This is an answer, probably, to those who say the arrival of the kingdom will take years and generations.
He affirms to his followers that the arrival of the kingdom is imminent. He assures his disciples that whatever he says will happen. Whatever he said about Jerusalem, war etc, did take place in history. But the arrival of the kingdom of God is happening.
