If you study the lives of Jacob and Esau, you will notice the reason why God rejected Esau and chose Jacob over him. The same thing with every man of God in the Bible, whether it be Moses, Elijah or David, you will discover that, the thing which God saw in Jacob was in all of them. The bible says, the eyes of the Lord run to and fro throughout the whole earth searching for those who are whole heatedly devoted to him (2 Chronicles 16:9). God is always searching for a man he can work through, not a group or a government, but a man. Every purpose of God in the earth can only be accomplished through a man, and this man must have that thing which was in Jacob and the rest of them, without this thing he cannot get the job done. The Bible tells us that God's election happens before birth (Romans 9:11), this means before anyone of those guys ever walked with him, he searched their hearts and found that thing.
Esau was a man who lived after the flesh, he lived to please mommy and daddy, a man pleaser, he only cared about what people thought of him. He didn't care what God thought of him, he only lived to please his parents. He would go hunting so that his father could be proud of him, a man with such an attitude cannot walk with God. He had no back bone, he lacked the boldness to stand on his own, he trusted in human beings. The same thing with Jesse sons, outwardly they looked like mighty men, but the Lord rejected all of them and chose David. Before rejecting them he said, “the LORD seeth not as man seeth; for man looketh on the outward appearance, but the LORD looketh on the heart” (1 Samuel 16:7).
If you look at Jacob he didn’t care what human beings thought of him, what mattered the most to him was the heart of God, what God thought of him. This was a man of the Spirit, he walked by faith and not by sight. Hebrews 11:6 tells us, “without faith it is impossible to please God”. Esau was a man of the senses but Jacob a man of faith. Jacob is that guy who is not afraid of doing the impossible whereas Esau only settles for what is naturally possible and shuns away from the impossible. The Bible says Moses “esteemed the reproach of Christ greater wealth than the treasures of Egypt” (Hebrew 11:26). The man chose the difficult path of faith over the pleasures of Egypt, he could have easily been second in command to Pharaoh but he refused to walk by sense, he saw the invisible God and believed for a greater life in Christ than the pleasures of sin. This is the thing that attracts God in a man, a heart of faith. A heart that believes in the impossible and the invisible.