In their investigation of God’s Word the bible , earlier Bible Students were keenly interested in the prophecies of the Christian Greek Scriptures relating to "the end of the world" and to Christ’s "coming." (Matthew 24:3, KJ)

By turning to the Greek text, they discovered that Christ’s "coming" was, in fact, a "pa·rou·si´a," or invisible presence.

Therefore, Christ had given his disciples information about the evidence of his invisible presence in the time of the end, not a future visible coming.

Along with their study, those Bible students had a keen desire to understand the Bible’s chronology in relation to Christ’s presence.

Without understanding all the details, those ealier bible students ,realized that 1914 would be a crucial date in human history.—Matthew 24:3-22; Luke 21:7-33, Int.

and now in this time of the end ,the understanding is abundant indeed .

That Jesus’ pa·rou·si´a is not simply a momentary coming followed by a rapid departure but is, rather, a presence covering a period of time is also indicated by his words recorded at Matthew 24:37-39 and Luke 17:26-30.

Here "the days of Noah" are compared to "the presence of the Son of man" ("the days of the Son of man," in Luke’s account).

Jesus, therefore, does not limit the comparison just to the coming of the Deluge as a final climax during Noah’s days, though he shows that his own "presence" or "days" will see a similar climax.

Since "the days of Noah" actually covered a period of years, there is basis for believing that the foretold "presence [or "days"] of the Son of man" would likewise cover a period of some years, being climaxed by the destruction of those not giving heed to the opportunity afforded them to seek deliverance.