We know God’s ways are higher than ours and there are several dualities in the Bible.
God created Adam and Eve and their firstborn were twins: Cain and Abel.
Angels fell and took daughters of men for wives.
Study Genesis 6:1-13.
The Earth became filled with violence through the offspring of these angels. God destroys the earth with the flood because of them and starts again later with Abraham (symbol of the Father) and Isaac (symbol of Jesus Christ).
Genesis 6:13: “And God said unto Noah, The end of all flesh is come before me; for the earth is filled with violence through them; and, behold, I will destroy them with the earth.”
Isaac married Rebekah, and they had twin sons: Esau and Jacob.
In duality, Adam and Isaac are the same; both symbols of Jesus Christ.
I Corinthians 15:45-47: “And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit. Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual. The first man is of the earth, earthy; the second man is the Lord from heaven.”
Isaac was willing to let his father, Abraham, sacrifice him as Jesus was willing to be sacrificed.
Genesis 22:9: “And they came to the place which God had told him of; and Abraham built an altar there, and laid the wood in order, and bound Isaac his son, and laid him on the altar upon the wood.”
Cain and Esau versus Abel and Jacob represented two manners of people.
Genesis 25:22-24: “And the children struggled together within her; and she said, If it be so, why am I thus? And she went to enquire of the Lord. And the Lord said unto her, Two nations are in thy womb, and two manner of people shall be separated from thy bowels; and the one people shall be stronger than the other people; and the elder shall serve the younger. And when her days to be delivered were fulfilled, behold, there were twins in her womb.”
Cain was of The Wicked One.
I John 3:12: “Not as Cain, who was of that wicked one, and slew his brother. And wherefore slew he him? Because his own works were evil, and his brother’s righteous.”
Esau was a fornicator and profane person.
Hebrews 12:16: “Lest there be any fornicator, or profane person, as Esau, who for one morsel of meat sold his birthright.”
Abel was righteous.
Matthew 23:35: “That upon you may come all the righteous blood shed upon the earth, from the blood of righteous Abel unto the blood of Zacharias son of Barachias, whom ye slew between the temple and the altar.”
Cain and Esau were the first born but neither of them received the birthright which goes to the first born. God could not let Jesus Christ be born through someone who was not righteous.
Abel and Jacob are the same. If Cain had not killed Abel then Abel may have been the father of the twelve tribes of Israel instead of Jacob.