People had faith in these things as it was presented from God's mouthpiece as part of the Good News.
Watchtower June 1 1968 page 331
On the Joyful March to Mankind’s Millennium
Arguing against a literal future millennial fule by Christ, some have claimed that such a teaching would chill the missionary ardour of Christians to make disciples of all nations. (Matt. 28:19,20) But not so! Today no people are more zealous in carrying out this missionary commission than are the Christian witnesses of Jehovah, who believe that the 1,000-year reign of Christ is literal and future. In comparatively few years these have grown to more than a million. Today they are carrying out this commission in 197 lands and islands of the sea and that in 169 languages. Last year they devoted 184 million hours to this work!
And no wonder. What good news they have to tell the people! They proclaim the good news that the millennial rule of Christ will begin with this generation and that it will mean ever so many blessings for the people :..
Faith is the assured expectation
In the Insight book under Faith on page 803 it says that the word used that is translated assured expectation is common to business documents and conveys the idea of something that underlies visible conditions and guarantees a future possession.
Like the title deed to a property.
In the
book "Man's
Salvation Out Of World Distress At Hand" on page 29 it says.
"After
all that we have gone through since 1914, our generation would be, of
all generations the "most to be pitied".Think
of it, though! Worthy ones of this generation of mankind will be saved alive
out of the rest of this world distress so as to survive the worst of it and
enter into God's Messianic new system of things and not need a resurrection
from the dead to life on earth! This is a valid hope well founded on what was
said by Jesus Christ..." (Evidently not)
“most to be pitied”
taken from 1 Corinthians 15 when Paul is talking of the resurrection of Christ
and our faith being in vain if this has not taken place.
To me it would be like taking what Paul said about the resurrection as pencilled in in a puzzle book if I were to take your view point.