Correct me if I'm wrong, but from what I understand, one of the major differences between Eastern Orthodox and Protestant theology is "ancestral sin."
Although Roman Catholicism's definition of original sin and Orthodoxy's view of ancestral sin are very similar, they do have subtly important differences.
These differences stem from the translation of the New Testament Greek text into Latin.
The consequences of the Fall spread to the whole of the human race. This is elucidated by St Paul: 'Therefore as sin came into the world through one man and death through sin, and so death spread to all men because all men sinned' (Rom.5:12). This text, which formed the Church's basis of her teaching on 'original sin', may be understood in a number of ways: the Greek words ef' ho pantes hemarton may be translated not only as 'because all men sinned' (Greek translation), but also 'in whom [that is, in Adam] all men sinned' (Latin Translation). Different readings of the text may produce different understandings of what 'original sin' means.
If we accept the first translation, this means that each person is responsible for his own sins, and not for Adam's transgression. Here, Adam is merely the prototype of all future sinners, each of whom, in repeating Adam's sin, bears responsibility only for his own sins. Adam's sin is not the cause of our sinfulness; we do not participate in his sin and his guilt cannot be passed onto us.
However, if we read the text to mean 'in whom all have sinned', this can be understood as the passing on of Adam's sin to all future generations of people, since human nature has been infected by sin in general. The disposition toward sin became hereditary and responsibility for turning away from God sin universal.
St. Augustine obviously took the Latin road in interpreting this verse, and consequently developed and elaborated on the nature of original sin. All of the Protestant Reformer's theology concerning the fall of man was rooted in the Augustinian school of thought, and consequently is slightly more similar to Catholicism than Orthodoxy.
What I'm trying to wrap my mind around is how this difference in interpretation reciprocally translates to rebirth in Christ.
The hinge-verse for me is:
...As one man’s trespass led to condemnation for all men, so one man’s act of righteousness leads to acquittal and life for all men. For as by one man’s disobedience many were made sinners, so by one man’s obedience many will be made righteous...so that, as sin reigned in death, grace also might reign through righteousness to eternal life through Jesus Christ our Lord (Rom.5:18-21)
Orthodoxy teaches that through birth we inherit Adam's fallen nature, but not his personal guilt. Likewise, in rebirth (baptism) we inherit Christ's redeemed nature.
Calvinism adheres to the doctrine of total depravity, leaning heavily on Augustine's view of original sin. According to this belief, man inherits not only a fallen nature, but Adam's personal guilt as well.
What are the doctrinal consequences of these differences in light of Romans 5:18-21?
This question is intended to specifically focus on how the Orthodox definition of "ancestral" sin differs from the John Calvin's Augustinian (Catholic) view of the fall of man.