Free Will Of Humans
The use of free will is to simply test you. God owes us nothing and He knows very well that if every wish of man is granted, there would be chaos and test would end prematurely when one of you wish for e.g destruction of the universe. So let Him handle the parameters like your wishes, He knows better than any of us and test must continue as per His wish so some of us are going to have our wishes denied when another person needs their test set up for them. Those who are proven to be obedient to God and do not abuse their free will to create evil in this testing ground we call worldly life are suited to have their wishes granted in Paradise. But here, you are going to sit in life that God has set for you, He is going to put in situation where you will have to use your free will to choose your desires or His obedience on the other side, between rebellion and gratitude, between evil and good. And then you will be rewarded accordingly.