The Kingdom of God is Within You by Leo Tolstoy Chapter 11 Page 33

shall come when the tribulation of men is greater than it has ever been, and when the Gospel of the kingdom of God, that is, the possibility of a new organization of life, shall be preached in the world unto all nations. (Matt. xxiv. 3-28.) But of that day and hour knoweth no man but the Father only (Matt. xxiv. 3-6), said Christ. For it may come any time, in such an hour as ye think not.

To the question when this hour cometh Christ answers that we cannot know, but just because we cannot know when that hour is coming we ought to be always ready to meet it, just as the master ought to watch who guards his house from thieves, as the virgins ought to watch with lamps alight for the bridegroom; and further, we ought to work with all the powers given us to bring that hour to pass, as the servants ought to work with the talents intrusted to them.