This is my personal point of view:
First of all you can find a general answer of your question in 51:56
And I did not create the jinn and mankind except to worship Me.
Now let's have a look at 46:14
Those are the companions of Paradise, abiding eternally therein as reward for what they used to do.
Here, you will notice that Allah promises an immortal life in paradise.
So, how is it possible that Allah forces Adam to leave jannah although Allah promises an
To answer this question you can now read 64:9
...And whoever believes in Allah and does righteousness - He will remove from him his misdeeds
and admit him to gardens beneath which rivers flow, wherein they will abide forever...
In this ayah the Arabic word jannah is translated as garden instead of paradise.
Indeed, one of the meaning of jannah is garden and therefore I personally do not believe that
Adam had been in paradise before he was tested by Allah.
Instead, it is more than likely that he already had stayed on earth in a beautiful oasis or something like that (Garden). After his sin he had to leave the jannah or garden.
It seems that Allah even has tested Adam on earth as like any other of us... This rule allows of no exceptions!
And I personally don't believe that Adam was the first human being on earth;
There are no leads on the first human being of Adam in the Koran.
The Koran tells us that he was the FIRST prophet but he was NOT the first human being!
For this reason, I think that other human beings besides Adam had existed, but Adam was the first protoype of mankind
who was able to differentiate between good and evil, the wrong way the right way (see 2:30).
In respect of the points I have mentioned I think that the story of Adam wants to show us
that the whole mankind after Adam will be tested by doing good things and by working for a better world (read Sura Asr).
Adam did a mistake, but this does not mean that we are guilty for his behaviour (53:38)
Namely, that no bearer of burdens can bear the burden of another;