God told Rebecca she was going to give birth to two sons and the older would serve the younger..God hated Esau before he was born. Was he being unjust?

God is omniscient ( All-knowing). He knows the end from the beginning and we have been predestined by him. He therefore knows those who'll be saved.

Those who are saved are saved, do what they may, those who are damned are damned do all they can.

Is that fair?

God might be a little unjust according to the thinking of humans but do you know this same God is merciful he forgives regardless of the sin but still yet many will reap the rewards of going against his word i.e the ten commandments e.t.c because he hath said in his word that no sinner will ever go unpurnished. he is not unjust because regardless of his hatred for esau he still prospered, regardless of what was predestined for jabeez with prayer his story was changed for good and there was a turnaround in his life. so GOD has given man the most important weapon of spiritual war so make good use of it and don't sit down to blame GOD in your situation. blame yourself for not utlizing the weapon GOD gave to you!