Why, even before Esau was born, did God hate him? Did God in the first earth age likewise despise Esau? Or does it really matter why, other than what Romans 9 makes very clear?
(for the children not yet being born, nor having done any good or evil, that the purpose of God according to election might stand, not of works but of Him who calls), it was said to her, "The older shall serve the younger." As it is written, "Jacob I have loved, but Esau I have hated." What shall we say then? Is there unrighteousness with God? Certainly not! For He says to Moses, "I will have mercy on whomever I will have mercy, and I will have compassion on whomever I will have compassion." So then it is not of him who wills, nor of him who runs, but of God who shows mercy. For the Scripture says to Pharaoh, "For this very purpose I have raised you up, that I may show My power in you, and that My name may be declared in all the earth." Therefore He has mercy on whom He wills, and whom He wills He hardens. You will say to me then, "Why does He still find fault? For who has resisted His will?" But indeed, O man, who are you to reply against God? Will the thing formed say to him who formed it, "Why have you made me like this?" Does not the potter have power over the clay, from the same lump to make one vessel for honor and another for dishonor? What if God, wanting to show His wrath and to make His power known, endured with much longsuffering the vessels of wrath prepared for destruction, and that He might make known the riches of His glory on the vessels of mercy, which He had prepared beforehand for glory, even us whom He called, not of the Jews only, but also of the Gentiles? As He says also in Hosea: "I will call them My people, who were not My people, And her beloved, who was not beloved." "And it shall come to pass in the place where it was said to them, 'You are not My people,' There they shall be called sons of the living God."
- Romans 9:11-26