I never feel that such discussions are useful to daily living. St Paul warned us to set aside differences for the sake of unity.
That being said, my understanding is that, at some point in the unknowable past, the human race chose to separate itself from the living God, which resulted in death. God knew this would happen and even allowed it in order to show His love by becoming one of us and bearing our death upon Himself, thus bringing us back into an even better union with Him.
All we really need to know is that man chose to disharmonize himself with God, and that "God became Man so that man might become God," to quote St. Athanasius. The consequence of separating from Life is death, which, according to St. Paul, is what the first man Adam brought into the world, and the second Man conquered.
Going off topic a bit...
I agree with Origen and other ancient writers who felt that this event is only allegorically told in the Adam and Eve story, especially considering that this theme of man's separation from God takes on various forms in the Old Testament. (In other words, I believe in differentiating between form and content.)
From Wikipedia:
In the first five chapters of Genesis the word אָדָם ( 'adam ) is used in all of its senses: collectively ("mankind"),[1:27] individually (a "man"),[2:7] gender nonspecific, ("man and woman")[5:1,2] and male.[2:23–24][15] According to the Jewish Encyclopedia, its use in Genesis 1 is generic, while in Genesis 2 and Genesis 3 the generic and personal usages are mixed.[12]
In Genesis 1:27 "adam" is used in the collective sense, whereby not only the individual Adam, but all humans, are created on the sixth day. The interplay between the individual "Adam" and the collective "humankind" is a main literary component to the events that occur in the Garden of Eden, the ambiguous meanings embedded throughout the moral, sexual, and spiritual terms of the narrative reflecting the complexity of the human condition.[16] Genesis 2:7 is the first verse where "Adam" takes on the sense of an individual man (the first man): the context of sex and gender, prior to these verses, is absent. The gender distinction of "adam" is then reiterated in Genesis 5:1–2 by defining "male and female".[15]
A recurring literary motif that occurs (in Gen. 1–8), is the bond between Adam and the earth ("adamah"). Adam is made from the earth, and it is from this "adamah" that Adam gets his name. God's cursing of Adam also results in the ground being cursed, causing him to have to labour for food,[3:17] and Adam returns to the earth from which he was taken.[3:19] This "earthly" aspect is a component of Adam's identity, and Adam's curse of estrangement from the earth seems to render humankind's divided identity of being earthly yet separated from nature.[8:21][17]
In the expulsion from Eden narrative, the woman is lured into dialogue on the serpent's terms, which directly disputes Yahweh's command (3:1-5).[21] Adam and the woman sin (3:6-8).[22] Yahweh then questions Adam and the woman (3:9-13)[23] initiating a dialogue. Yahweh calls out to Adam using a rhetorical question that is designed to prompt him to consider his wrongdoing. Adam explains that he hid out of fear because he realized his nakedness.[24] This is followed by two more rhetorical questions designed to show awareness of a defiance of Yahweh's command. Adam then points to the woman as the real offender, then accuses Yahweh for the tragedy.[25]
After a series of blaming occurs, Yahweh initiates judgement on all culprits involved (3:14-19).[23] A judgement oracle and the nature of the crime is first laid upon the serpent, then the woman, and finally Adam. In Adam's punishment, Yahweh curses the ground from which he came, and then receives a death oracle.[26]
The chiasmus structure of the death oracle given to Adam in 3:19, is a link between man's creation from "dust" (2:7) to the "return" of his beginnings.[27]
A you return
B to the ground
C since (kî ) from it you were taken
C' for (kî ) dust you are
B' and to dust
A' you will return
The reaction of Adam, the naming of Eve, and Yahweh making skin garments are described in a concise narrative (3:20-21). The garden account ends with an intradivine monologue, determining Adam and the woman's expulsion, and the execution of that deliberation (3:22-24).[23]