I’ll give some possible answers; don’t expect me to have the proof, because we are on “what if†territory here
How much do they know about earth?
They know all about it, because we are one of their laboratory experiments that they have started some time ago. (They also provide the exact date.)
Are they able to speak for their species as a whole?
Yes, because in their advanced society, their individualism and nationalism was long before dismissed and replaced with the advantages of an open society that shares everything, including information.
Is their opinion on the belief in a deity a stance taken by all of them?
They know we are the product of their experiments so there are no deities involved (directly) in our “creationâ€. The fact that they themselves are the product of some “divine intervention†is not yet established, as there is not enough proof for/against it. For the moment they are waiting for the race that started
them as an experiment.
How hard is the evidence?
Solid crystal proof. All the history of the Earth is recorded within a few crystal storage units and available for playback in full 3D, surround sound - holographic theaters for us to enjoy.
Too many things come into question and so I really don't think it would make the Jehovah's Witnesses (as a group) change their beliefs. Now individuals might take what they say and run with it but are we sure that the evidence wasn't fabricated in some way or was there any bias allowed to creep in?
[emphasis added]
Well, you should realize that I as a skeptic think that all the “proof†that you can find in the “holy texts†is fabricated and full of obvious bias.
The only person that I know of that scientifically proved there was no God was Homer Simpson!
In this case he is my personal hero!
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From that I tend to assume that it really does not matter in the story of God's relationship with us and the story of salvation. So who knows, there could be life, and that life could claim that there is no God, but they'd need some pretty good evidence and I'm skeptical that such evidence can ever be found.
You see, I find it interesting that (theist) people find it easier to believe that there are extra-terrestrial out there than that our deities are nothing more than human invention.
I completely agree that “the story of salvation†is important, as the most effective way of spreading morality. Yet I strongly believe that it is more important to acknowledge the reasons behind it and apply that morality because it is
for the Greater/General Good than to blindly go ahead with the story and making claims that openly contradict scientific knowledge, as a result of the “holier that you†mentality.
A.
It's all just a matter of interpretation.