Genesis says that Adam and Eve had three children –Cain, Abel and Seth– but uses words that don’t clarify whether they were all male and children of both of them.
“The man knew Eve, his wife, who conceived and gave birth to Cain, and said: ‘I have acquired a man with the favour of Yahweh.’ She gave birth again, and had his brother Abel. Abel became a shepherd and Cain a farmer.”
“Adam knew his wife again, and she gave birth to a son, whom she named Set, saying: “God has given me another descendant instead of Abel, because Cain killed him.” 
“Adam was 130 years old when he begot a son in his likeness, according to his image, whom he named Seth.”
Since Genesis doesn’t say that Adam begot Cain, and tells us that after giving birth to Cain, Eve claimed to have begotten a male with the help of Yahweh, it isn’t clear who begot him. It also isn’t clear who begot Abel because Genesis only says of him that he was Cain’s brother. And while Genesis says that Set was a son in Adam’s likeness and his image, it doesn’t say this about Cain or Abel.
The fact that Genesis says that Adam knew his wife again and she gave birth to a son, whom she named Set, and later says that Adam begot Set, has misled many theologians. Because in this particular case the expression “X met his wife and she gave birth to Y” matches the following information that X begot Y, they assume this is always the case. They completely ignore that there may be a reason why Genesis doesn’t say, “Adam begot Cain”: one can be sure of who one’s mother is, but not who one’s father is. This is why Jews consider that one is a Jew when his mother is a Jew.
Genesis says that Cain was a male, but doesn’t say that also Abel was a male. Cain and Abel may have been twins because Genesis doesn’t say that Eve conceived again. The information that Abel was Cain’s brother is insufficient to conclude that Cain was a male because the word brothers is also used to refer to the relationship between sons and daughters of the same father or mother.
Brothers may have one or both parents in common. All half-brothers are also brothers, but not all brothers are half-brothers.
If we pay close attention to the exact words Genesis uses, we observe that sometimes its protagonist is called God (the one who created the human being in His image), other times Yahweh God (the one who created the human being out of dust from the ground) and still other times Yahweh.
“Cain brought some of the produce of the soil as an offering for Yahweh, while Abel for his part brought the first-born of his flock and some of their fat as well. Yahweh looked with favour on Abel and his offering. But he did not look with favour on Cain and his offering, and Cain was very angry and downcast. Yahweh asked Cain, ‘Why are you angry and downcast? If you are doing right, surely you ought to hold your head high! But if you are not doing right, Sin is crouching at the door hungry to get you. You can still master him.”
Since Cain was a farmer and Abel was a shepherd, we can assume that Cain was still following the vegetarian diet that God had prescribed to Adam, while Abel had stopped doing so. It doesn’t make sense that God looked with favour on Abel and his offering. Therefore, we must wonder whether perhaps Abel somehow benefitted from offering the firstborn of his flock.
The story of Cain and Abel is the first to mention the firstborn. The fact that the Bible later refers to the tradition of sacrificing the firstborn, encourages us to wonder whether among the firstborn of Abel’s flock was his own firstborn son. The god to whom the first-born was sacrificed was called Moloch, but he was also known by the name Baal, which has the same consonants as Abel.
Cain killed Abel. Although Abel was not an innocent victim, Yahweh didn’t like Cain taking justice into his own hands. Therefore, He cursed Cain: “Even though you till the soil, it will no longer give you its strength. You will be a restless wanderer on earth all the days of your life.”
When Cain later complains that his guilt is too great and that whoever finds him will kill him, Yahweh replied: “On the contrary, whoever kills Cain, will pay it 7 times.” Assuming that Yahweh refers to a sevenfold vengeance means ignoring that Yahweh didn’t kill Cain for having killed Abel. Why then would He avenge Abel’s death 7 times?
We understand what Yahweh said to Cain only when we later come across the difference between pure (7 pairs of each species) and impure (1 pair of each species) animals, and investigate the best way to repopulate the Earth with seven pairs if they wanted to avoid inbreeding as much as possible. The best way was that, with each new generation, each male lineage crossed with each one of the 7 female lineages, in such a way that, 8 generations later, it crossed the first one again.
After Cain killed Abel, Yahweh asked, “Where is your brother?” and Cain replied, “Am I my brother’s keeper?” Genesis refers here to the fact that they were both the fruit of the same male line crossing the same female line.
The story of Judah and his daughter-in-law Tamar informs us of the tradition of securing offspring for a deceased older brother through his widow marrying another brother. Cain could thus have secured offspring for Abel.
Cain’s genealogy mentions 7 generations between him and the last generation: that of Jabal, Jubal, Tubal-Cain and Naamah. Lamech, the father of Jabal, Jubal, Tubal-Cain and Naamah, said to his wives: “Adah and Zillah, hear my voice: women of Lamech, listen to my words: I killed a man for wounding me, and a boy for striking me. Sevenfold vengeance for Cain, but seventy-sevenfold for Lamech.
Genesis says that Adah gave birth to Jabal, the father of those who live in tents and raise cattle, and that her brother was Jubal, the father of those who play the zither and the flute. And of Zillah it says that she begot Tubal-Cain, the father of all the copper and iron forgers, and that her sister was called Naamah.
In the names of the 3 sons of Lamech we find the combination of the BL consonants that form the name Abel. The name Tubal-Cain also refers to Cain. The fact that Genesis says that Zillah begat Tubal-Cain, and that this term is normally used for a relationship between a father and a son, indicates that, through Tubal-Cain, Zillah recovered the lineage of Abel.
Lamech warned his wives about the sevenfold revenge for the death of Cain because Cain reincarnated in Jabal and Abel reincarnated in Tubal-Cain. The child that his wife Adah gave birth to thus caused the death of Cain, while the son that Zillah gave birth to recovered Abel’s lineage.
Jabal, Lamech’s son in Cain’s genealogy, and Noah, Lamech’s son in Seth’s genealogy, refer to the same person. If Jabal was the father of those who live in tents and raise cattle, the generations before him were farmers. Set’s genealogy also refers to the change of occupation from agriculture to herding because it says: “Lamech begot a son and named him Noah, and said, ”He will comfort us in the labour and painful toil of our hands caused by the ground that Yahweh cursed.”
Other information that indicates that Jabal and Noah were the same person is that the first mention of someone living in a tent refers to Noah; Genesis doesn’t say that Lamech begot Noah, but that he begot a son and named him Noah, thus indicating that it was a nickname; and that the Lamech in Cain’s genealogy mentions a 77-fold revenge, while the Lamech in Set’s genealogy dies when he is 777 years old.
Jabal was the reincarnation of Cain, and Tubal-Cain the reincarnation of Abel. But while Cain and Abel had the same mother, Jabal’s mother was Adah and Tubal-Cain’s mother was Zillah. If Adah and Zillah were sisters, they belonged to the same female lineage.
The 77-fold revenge –77 is 11 times 7– refers to the 11 generations between Lamech’s sons and Abraham.
The next 10 articles are:
8 PHILOSOPHY versus THEOLOGY 0 Cain’s descendants
9 PHILOSOPHY versus THEOLOGY 0 The Flood
10 PHILOSOPHY versus THEOLOGY 0 Noah
11 PHILOSOPHY versus THEOLOGY 0 Evil since childhood
12 PHILOSOPHY versus THEOLOGY 0 Repopulating the Earth
13 PHILOSOPHY versus THEOLOGY 0 The tower of Babel
14 PHILOSOPHY versus THEOLOGY 0 A unique language
15 PHILOSOPHY versus THEOLOGY 0 Whores
16 PHILOSOPHY versus THEOLOGY 0 20 patriarchs
17 PHILOSOPHY versus THEOLOGY 0 Abraham and Sarah