But it doesn't say how old Adam was when Cain and Abel were born. He could have been 100 by the time that happened. You don't even know how long they walked around in the Garden before they were cast out.
I said exactly this two posts before yours. So you repeat what I say and then appear to claim it as your own argument.
Obviously I understand that point, I wouldnt have said it otherwise
I'm trying not to inject personal opinion disguised as knowledge into this discussion.
Yes you are, you are injecting your personal opinion to claim that there were other people alive on earth at the time unrelated to Adam and Eve that would want to kill Cain and therefore attributing a major discrepancy to the Creation account, yet there is no textual support for this personal opinion of yours. (If that is not your claim, please ignore all of this post and restate it succintly and we start again!)
Cain was afraid that 'anyone' would kill him. The inference from that is that he thought that everyone would want to kill him. It was his own family that he is thinking of whether that be Adam himself, or any existing and future generations.
Oh, I see. God's perfect, holy Word only gives us sketchy details with which we are to derive our own conclusions, however contradictory they may be.
Hermeneutics is not deriving our own conclusions, and there are no contradictions here. Only you are enforcing a contradiction on the text in this case.
Yet, later on when it talks about people marrying people and having children, it seems of vital importance to the author to name hundreds of names. They're not important? They're the very first people inhabiting this planet and propagating the species!
Sorry for the bad wording, I shall restate for clarity. What is recorded in the scripture is important for us to know. What is not recorded is not important for us to know. Honestly, I would have loved to know more about Adam, and his family, what they did, how the lived, what they invented. As fascinating as these things may be, they do not have any relevance to us in understanding the Gods purpose for our life. There is only 3 chapters devoted to the "beginning" the rest is dedicated to redemption, and it is the latter that is the important part.
Furthermore, if you're assuming that they had offspring while still in the Garden, how horrible would it have been of God to have expelled all of them from the Garden when only Adam and Eve disobeyed Him?
I do not see that he is saying Adam and Eve had children in the garden, though, childbirth was not a new concept to them, see Gen 3:16. In any case if you are right, then regardless, all of mankind are responsible for the consequences of their actions. Our children reap the benefits of our good works and suffer from the impact of our bad. If that was never the case, then nobody would have to be responsible for their actions, and they could do whatever they liked.