In the book Man's Salvation Out of World Distress At Hand 1975 Watchtower Bible and Tract Society on page 47 it says,
The glorification of Jesus Christ in heaven after his extraordinary sufferings as a man on earth was good news, Gospel, Evangel "Nevertheless," writes the apostle Paul with special reference to his own people, "they did not all obey the good news. For Isaiah says: 'Jehovah, who put faith in the thing heard [from] us? So faith follows the thing heard. In turn the thing heard is through the word about Christ." -Romans 10:16,17.
Page 48.
A similar thing can be said today. "They did not all obey the good news." This, even after the christian witnesses of Jehovah have spent more than sixty years in proclaiming the the "times of the Gentiles" ended in the autumn of 1914 C.E. amis the first world war and that then Jehovah's "servant " recieved a new elevation by being exalted to the throne of the Messianic kingdom...
In the face of the relatively small proportion of the world's population that has put faith in the "thing Heard [from] us" or proclaimes by us, it can truthfully be said: "They did not all obey the good news."
I understood this to mean we should have faith in the 'good news.' 'Faith is the assured expectation of the things hoped for...'Hebrews 11. I believe its been described as the title deed. It's sure, it will happen.
Page 29.
"After all that we have gone through since 1914, our generation would be, of all generations the "most to be pitied". (bold mine)
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..."
Watchtower June 1 1968 page 331
On the Joyful March to Mankind’s Millennium
'Arguing against a literal future millennial rule 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 :..'
So I feel that if we were to apply Paul's words in Romans 10 about having faith in this good news and it doesn't occur what happens to our faith? Maybe this explains how I come to where I am regarding the Witnesses.
As I understand it part of the apostle Pauls good news that he preached was the resurrection of Jesus Christ and in 1Corinthians 15:15 he talks of being a false witness if this did not occur and says 'because we have bourne witness against God' (NWT) if he wasn't raised.