PSacramento replied this way:
It was a test of faith for Abe, so that Abe could see for himself that HE had the faith to do all that God said he would.
When going up to the mountain Abe told his servants that THEY would return, Abe knew that somehow God would provide that they BOTH would return alive.
God knew the outcome and knew that nothing would happen to Isaac.
For all we know God could have decided to allow Abe to kill Isaac and then raise Isaac from the dead with no meomory of what happened.
The story could have gone many possible ways.
So, if Abe had decided that he wouldn't kill his own son, descendants or not, would he have received the prize? You say that "the story could have gone many possible ways". I say we don't know. We just cannot decide what God would have done under this or that situation. All we know -or, more exactly, what people who believe in the Bible claim we know- is that YHWH asked Abraham to go kill his son, and Abe did that. Because of that, he received the promise that his descendants would be countless. The rest is speculation.
The fact that the rest is speculation, however, does not mean we cannot see that some things are not logical:
If Abe somehow knew he would return with Isaac alive, why is there any value in his going up the hill? Abraham would have been pretending to obey, when in fact he would have known that nothing would happen. God would have been duped.
I would assume that Abe would know the extent of his own faith. It is as if you were to ask me whether I know the extent of my own love for, say, Ms. DGP (if there were any). There should be no need for someone to test him so Abraham himself could know that. I will kindly ask you to notice that, if Abe didn't know the extent of his faith, then perhaps he can hardly be expected to "know" that Isaac would return alive. The story would have no value if it were all no more than pretending to have faith.
If the test was meant for Abe to kno whe would do anything God would request, is there, then, value in simply following God's orders and doing things just because God wants them done?
More generally, my question was meant to raise a point. Yes, there are religious people who would be kind and nice just for the sake of it. People who do good just because doing good is the right thing to do. But there are many others who behave religiously because they expect a reward, and not just among Jehovah's witnesses but among probably every religious group. They do what they do just because God told them to, and in being obedient (like Abraham) they expect to find a reward.
Good people are indeed deemed to go to hell if they don't belong to the self-appointed "Jehovah's organization". We know that for a fact. It is also what many other religious denominations believe. Doing good for its own sake is not considered "as good" as doing things because the higher being (or beings) demand so.