(Modern) Judaism is usually described as not subscribing to the original sin doctrine, where humanity is seen as inherently doomed per the actions of Adam and Eve. (It looks like it's a generalisation, but I've seen similar statements made elsewhere. It's not an unreasonable reading of the beginning of Genesis as far as I'm concerned, but I digress.)
Now, the Christian understanding I grew up with (somewhat evangelical in nature, prone to "pop-theology") was that we cannot save ourselves -- we cannot achieve goodness because of Adam's actions:
Therefore, just as sin came into the world through one man, and death came through sin, and so death spread to all because all have sinned—sin was indeed in the world before the law, but sin is not reckoned when there is no law. (Romans 5:12-13, NRSVA).
So this is not merely about Adam's actions causing death, since "sin came into the world through one man". (Whether or not this is the correct reading of Genesis seems ambiguous, but that's irrelevant here, and I probably wouldn't be able to solve that question without drastically improving my Hebrew knowledge.) This is reinforced by the earlier statement that "all have sinned and fall short of the glory of God."
What is the historical cause of this disparity in Jewish and Christian (per my experience of Christianity) attitudes to human nature? Was this an influence of some contemporary (New Testament times) strain of Jewish thought, or perhaps it is linked to other influences ("foreign" ones, or perhaps ones that came later)? Or, to put it another way, what is the history of this doctrine in the Christian church - did the early church have similar views as modern Christians, or did the doctrine evolve over time?
Note: I'm almost certain I might have simply missed some of the context of the Epistles, but I'm asking as it seems like a more efficient way to figure this out.