do you mean that as in, "heaven isnt explicitly promised?"
or that heaven doesn't sound great?
I mean as: Heaven is probably same as hell on the long run.
Why?
I don't know what really Bible says but the picture that is common in public sounds like a bad scenario.
For example, you like writting books but about what you will write in heaven?
If you start to write novels you will have a problem becuse there is no infinite number of novels you can write without staring to repeat with time.
Your mind has boundarys and its operates inside of them.
But there is so big number of novels that can be written that it is fun to do it once again. but with time it is unavoidable that you start to repeat yourself once again. What will you do then? Start another cycle?
What will you do after 10 cycles ? 100? 10000? 1000000?
Will you still write novels?
What after 1000000000000000000000000000000000000000000000 cycles ?
I mean you can mix writting with other activity but problem is still out there.
What will you do when that huge number that is writting up there will be number of zeros after number 1 .
There is a fact that you forget things with time but you always will be conscious of the fact that you have done this so many times that you will even need thousands of years to even say the number how many time did you do something.
(becuse it is that Big)
All people that go to heaven could ask god to delete their memory.
But in that case people will figure out what happened quite fast and once again you have same problem.
Since you can't die, the problem will be there forever always behind you and ready to destroy any fun that comes your way.
Since you can't die you really can't experiance any real adventure becuse chance of survival is 100%.
What will you do? Ask God to destroy you somehow?
The only way to avoid this problem is that after death god turns you into something else. The point is that your human consciousness is no more so that you can grow and expand further.
But in that case you have another problem. If God can turn good person into something else why can't he do the same with the bad person.
If he can change entire mental concept I don't see why he/she/it can't destroy tiny part that makes someone good or evil?
So all logical conclusions lead to sitation that there is no good and evil or right and wrong in reality we live in. (Heaven and hell included)
I say this becuse all of us will get the benefits or no one will on the long run. If all of us don't get the same path that is not fair at all. Becuse you are not guilty for the fact that you have personality disorder or that your parents did not love you when you were a baby.
If right and wrong do exist, all of us are predetermined to eternity we will not like. But if all of us will be turned to nonhumans, something might just come out right.
Or the truth is something so abstract that human brain can't do anything about the problem. Why so may people think that there will be the end of the world soon. It is because world without the end is hard to understand and/or accept.
Same works for reality without God.