The genealogy of Cain is given briefly in Genesis 4:17-24. However, this was not the line that led from Adam to Noah, and all other lines of descendants were destroyed in the flood – including Cain’s descendants.
The genealogy of Adam goes through his son Seth to Noah (Genesis 5:3-32) and this is the part of the family tree that matters in the story of good and evil. In general, the Bible gives many more genealogical details of righteous people than of evil people like Cain.
Cain is not mentioned because Seth is the important son. If a father has many sons not all are mentioned just the important ones.
Josephus claims that shem married maria a daughter of cain thus taking cains lineage onto the ark. Jesus refers to cains lineage when he says Ye are of your father the devil and he was a liar and a murderer from the beginning. Catholic tweak here using devil.. the devil never killed anyone the devil is not allowed to kill (if he existed, devil is metaphor for flesh quite often) Cain killed and then he lied about it.
If he existed??????? Devil’s not allowed to kill??? Where are you getting this misinformation?
Because Cain is not of Adam’s seed.
The lack of including Cain the the genealogy is the same as telling a story and not giving every minute detail.
For example. If Micheal drove Jane, Sarah, and me to go get gas and to the store to get a birthday cake for Jake,but I told the story “Sarah and I went to the store and to get gas and you will not believe what happened…”
Was Micheal and Jane not important? No. It is not needful for the example I was giving.
It is the same with Cain. It’s not that Cain is not important. It is only that the focus is on Seth because through his descendants will come Jesus Christ.
Eve continued in birth…she had twins. Cain’s father Satan…he Satan seduced Eve…sexually planted his seed. Hence father of lie etc. and told who his father was/is. Today it is possible for women to be pregnant with twins by 2 different men. This is my understanding why Cain’s lineage wasn’t mentioned. Satan his true father.
Because he isn’t the son of Adam but the son of Satan. Eve was beguiled.