From the time Iwas a lad, I would constantly hear devout Christians proclaim Christ is coming soon.
I have now lived some years since, and Jesus has not returned as yet. "Soon" appears to be a relative, or is it? The bible states that a thousand years to God is but a day, but is this the reason why Christians should proclaim Jesus Christ is coming again soon for the period of judgment? No I do not think this is the case alone.
Christians should proclaim Jesus is coming soon, because the bible tells them they should, and because of the relatively short life-span of the average person.
The bible states that when a person dies he has no indication of what is happening around him, or the amount of time which has passed after his death. A person will only become conscious when the dead rise at the second coming of the Lord Jesus Christ.
Therefore these devout Christians who spoke of Jesus Christ coming soon were quite correct, because the person who dies tomorrow will die in 24hrs or less, and his/her understanding of time will be when Christ returns, and to that person Christ would have returned when they died.
Since the average person dies within 60-80 years in the scale of things this is relatively short and God would have returned soon.
It is therefore imperative for those who don't know Christ to get to know him by reading his word in the bible which has almost everything a person needs to know.