This totally belongs in the Spirituality and Railgun thread
To me, the whole "Adam and Eve as first people" is not really correct in a straight up "Only these people existed" sense. (I do not ascribe to dogmatic beliefs of this nature. Fossil records show quite a few early hominids of many stripes and types. Guess which one I put more faith in.) More reasonable is to look deeper at the context. God says "Wait, nobody is tilling the earth!" (Eg, agriculture is not a thing.) God creates a set of humans for the purpose of doing agriculture. These are Adam and Eve. He gives them special favor.
Why do I say this?
Well-- First up, the "Nobody is tilling the earth!" is right there in Genesis 2.
4 These are the generations of the heavens and of the earth when they were created, in the day that the LORD God made the earth and the heavens, 5 And every plant of the field before it was in the earth, and every herb of the field before it grew: for the LORD God had not caused it to rain upon the earth, and there was not a man to till the ground. 6 But there went up a mist from the earth, and watered the whole face of the ground. 7 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul. 8 And the LORD God planted a garden eastward in Eden; and there he put the man whom he had formed.
Agriculture is very much a part of this early narrative, since without it, any of the things these descendants are attributed to makes no sense. We know with certainty (thanks fossil record!) that people existed for thousands of years before inventing agriculture, or producing cities. It is only because of dogmatic beliefs that the assertion that Adam and Eve must *ahem* "
Absolutely be the first people or else the sacrifice of the christ makes no sense!!". It makes things a lot less tidy and neat if there are other people in the world at this time. However, this myth is focused on explaining why this specific group of people is special, and such-- as is the practice with basically every culture's genesis story. This story is about "These people", and not "those other people", and so-- those other people are not mentioned. Easy as that. Else, why even mention that tilling the soil bit in the first place? What does it delineate? If there are no other people at all, why bother with shining a spotlight on agriculture at all?
This is further given some weight, because later on it says that Cain was exiled to "The land of Nod" (interpreted as "land or state of wandering") in genesis 4. Then, not just a few verses later-- WHOOP, Got a wife, had a baby, built a city, named the city after the baby.
You are left with 2 possible explanations for this.
1) (the one favored by apologists)-- Cain married one of his unnamed sisters, and because of how badly women were treated in this culture, she had no say in the matter and was exiled with him.
2) there were other people out there, cain found one of these wanderers, married her, and had kids, then built a city.
I favor choice 2. Not only is it better supported by fossil records, (which CLEARLY show human habitation for a protracted period before the invention of agriculture), it also plays into how and why names are given to places and people in the bible. EVERYTHING has allegorical names. How could it be a land of wandering, if nobody is wandering in it? If one person is sent there, wouldnt it be a land of exile instead? Why name it NOD, and not the appropriate alternative? Also, why is Cain paranoid of being murdered out there, IF NOBODY LIVES THERE?! Too many things just do not add up for option 1 to be the preferred choice.
For starters, it takes more than just two people to build a freaking city-- Division of labor is totally a thing-- You need masons, architects, metal workers, craftsmen of various kinds--- You do not get those ex nihilo. NOW-- this guy, who being blessed by the divine by his origin as being "made for agriculture/culture", could insert himself into a more hunter-gatherer group, and direct them in the needed divisions of labor, and thus produce a city. Which totally makes sense-- but you do not get that from option 1, unless god also kicks a buttload of other people out of Eden. This does not even get started with explaining where the inhabitants of such a city magically appeared from-- To be a city, you need people living in it. Not just a few either, you need quite a lot of them to make a city function. God would have to be working overtime kicking people out of Eden to have that many people on hand to build, and operate a city. If he was doing that, it would be important to the narrative, so why no mention?
The "Those people are not relevant to the story until they interact with the chosen" angle makes it all go away. It just makes the apologists sad pandas. I don't care if it makes them sad. It's the more sensible interpretation.
Lilith, as Trekkin states, is a much later invention, and is the result of combining the myths and legends of a contemporary (and probably older!) culture with those of this demographic, as part of a cautionary tale about the dangers of insubordinate women.