Lets continue on and see how more stupid it gets:
Cain killed Abel, did God kill him like he did with others? Seems like it was
a known law amongst God's people back them about the eye/eye thingy!
No, he put a mark on Cain, and People who did bad to him were to be punished!
Quest #1: Did not Adam have other children? What purpose would have done to save him?
Quest #2: If Adam/Eve were forefathers to all, then why would cain need a mark? Would not everyone around
be sisters, brothers, children, nephews, nieces, etc? They would all know him, huh?