Christ's words [Matt. 24:2] had been spoken in the hearing of a large number of people, but when He was alone, Peter, John, James, and Andrew came to Him as He sat upon the Mount of Olives. "Tell us," they said, "when shall these things be? and what shall be the sign of Thy coming, and of the end of the world?" {LDE 32.1}
Jesus did not answer His disciples by taking up separately the destruction of Jerusalem and the great day of His coming. He mingled the description of these two events. Had He opened to His disciples future events as He beheld them, they would have been unable to endure the sight. In mercy to them He blended the description of the two great crises, leaving the disciples to study out the meaning for themselves.--DA 628 (1898). {LDE 32.2}
Time of Christ's Return Not Known
Many who have called themselves Adventists have been time-setters. Time after time has been set for Christ to come, but repeated failures have been the result. The definite time of our Lord's coming is declared to be beyond the ken of mortals. Even the angels, who minister unto those who shall be heirs of salvation, know not the day nor the hour. "But of that day and hour knoweth no man, no, not the angels of heaven, but My Father only."--4T 307 (1879). {LDE 32.3}
We are not to know the definite time either for the outpouring of the Holy Spirit or for the coming of Christ. . . . Why has not God given us this knowledge?--Because we would not make a right use of it if He did. A condition of things would result from this knowledge among our people that would greatly retard the work of God in preparing a people to stand in the great day that is to come. We are not to live upon time excitement. . . . {LDE 33.1}
You will not be able to say that He will come in one, two, or five years, neither are you to put off His coming by stating that it may not be for ten or twenty years.--RH March 22, 1892. {LDE 33.2}
We are nearing the great day of God. The signs are fulfilling. And yet we have no message to tell us of the day and hour of Christ's appearing. The Lord has wisely concealed this from us that we may always be in a state of expectancy and preparation for the second appearing of our Lord Jesus Christ in the clouds of heaven.--Letter 28, 1897. {LDE 33.3}
The exact time of the second coming of the Son of man is God's mystery.--DA 633 (1898). {LDE 33.4}