Luke 21:29

And he spake to them a parable: Behold the fig tree, and all of the trees: when they now shoot forth, ye see it and know of your own selves that the summer is now nigh. Even so ye also, when ye see these things coming to pass, know ye that the kingdom of God is nigh.

And all the trees ... These words seem to have been added by Jesus to prevent the interpretation of this fig tree as Israel; but, of course, that is what some have done anyway, with the deduction that when Israel starts budding out (giving signs of conversion to Christ), the glorious kingdom is about to appear! The conviction here regards such views negatively. This parable simply means that the progress, or lack of progress, of God's will among men will be plainly evident in the actions of men themselves. In our day, the trees are shooting out the leaves and branches all right; but what is indicated? Is it an increase of righteousness, or wickedness? The man who cannot answer has simply not looked. Jesus said, "Behold!"

The kingdom of God ... as used here is apparently a reference to the "eternal kingdom" (2 Peter 1:11), which is the state of believers after the Judgment.