Consider what happens if we remove that reward: What if those that refused to worship the Roman gods are treated no different than those that did? What if those that died in the arena are simply resurrected to life on earth just the same as those who escaped punishment by burning incense to the Emperor's diety? What reason would there be for dying in the arena at all? --None whatsoever. Remove the heavenly reward and you remove the reason to be faithful.
The situation is virtually the same in a modern setting. Why convert to the JW faith? Why go to all the meetings, go out knocking on doors, refuse to celebrate holidays, etc.? JW's do this because they, like the early Christians, believe that their salvation is at stake. For non-anointed JW's that salvation is described at Revelation 7:9-10.
What happens if we remove that reward? What happens if JW's simply grow old and die and are eventually resurrected to life in paradise just like everyone else who never bothered with the JW faith at all? What reason would anyone have for being a JW? --None whatsoever.
Take for example, a fictional JW family. The grandparents were baptized as adults in the late 1930's and never considered themselves to be anointed. They were the only members of their respective families to become JW's. They've been dead for 20 years now. How is their fate any different than all their "Unbelieving" brothers and sisters and cousins that never bothered with the JW faith? In JW theology, there is no difference. They're all going to be resurrected.
Any way you look at it, an "Earthly hope" is not a doctrine that can be taught longer than about a generation or so. It's only the proximity of the end and the prospect of not having to die that makes it viable. Remove that reward and you remove any reason to be faithful.
JW's view the 'earthly reward' as the default position lost in paradise by Adam and Eve. The heavenly hope is an abberation to create an administration (govt) to restore that default position, per Milton's poem "Paradise lost, paradise regained."
But before this default position is restored, the Biblical God is going committ genocide on an unimaginably horrific scale. He is going to exterminate the great majority of humankind, billions of them at Armageddon. They will deserve it, Christiniaty teaches, because we are all born with Adamic sin and the wages of sin is death. There will be no pity or mercy, they all had their chance when JW's came offering Awake and Watchtower magazine's on Saturday mornings, if you were lucky enough to be in a country where they did that. Those unfortunate billions unfortunate enough to live in China, Indian, or Muslim countries will be slaughtered on account of their 'community responsibility' for having leaders who never let the JW's get a foothold in their country.
Jehovah by his own standard of justice is forced to do it, he has no choice. He is compelled to commit this global slaughter by some unfathomable higher moral standard that is utterly incomprehensible and too horrific to contemplate for all human beings, except perhaps to persons such as Genghis Khan, Hitler, Stalin, Pol Pot, Kim Il Jong, etc.
And so it all boils down to the 'reward' for JW's remaining faithful to the organisation being escaping this terrible global slaughter by their version of God. He's an angry, vengeful God, who has been saving up his pent-up rage and hatred of mankind all this time, just waiting for the time to finally wipe them all out. A God of love would never torment people forever in hell, he will only just send hordes of angels and Jesus to kill billions of them, including bad little girls and their dollys and naughty pet dogs, like rats infesting a house. Much more reasonable.
Thus Satan will be proven to be a manslayer and Jesus praised as the saviour of the world.
It's such wonderful good news JW's preach, wouldn't you agree? You must be blind not to see it.
