The false doctrine of Original Sin

Ezekiel 18:19-20 "Yet you ask, 'Why does the son not share the guilt of his father?' Since the son has done what is just and right and has been careful to keep all my decrees, he will surely live. The soul who sins shall die. The son shall not suffer for the iniquity of the father, nor the father suffer for the iniquity of the son. The righteousness of the righteous shall be upon himself, and the wickedness of the wicked shall be upon himself.”

The notions of inherited sin and inherited guilt are nowhere to be found in Jewish tradition. Neither is there any indication that these ideas were held in the Church prior to the 5th Century AD.
The doctrine of “Original Sin” originated with Aurelius Augustine, Bishop of Hippo, in North Africa. The central passage of Scripture for this doctrine is Romans 5:12
“Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned” (English Standard Version).

Notice that the passage says that death passed to all. It does not say that sin or that guilt passed to all men. This is an obvious reference Genesis 2:16-17
"You are free to eat from any tree in the garden; but you must not eat from the tree of the knowledge of good and evil, for when you eat of it you will surely die."
Adam did indeed die on the day of his disobedience, but his death was not physical; rather it was a spiritual death. Just as physical death is the separation of man's spirit from his body, so spiritual death is separation of man from God. It is the opposite of spiritual life, which is fellowship and communion with God.
Spiritual death is separation, alienation, from God. It is not something wrong inside of man, but a negative or wrong relationship between man and God. Spiritual death is like a barrier between man and God.

A careful interpretation of Romans 5:12 depends upon the Greek prepositional phrase eph hos. This phrase is made up of a preposition (epi) and a relative pronoun (hos).
The preposition has several different meanings depending upon the immediate context and the case of the noun or pronoun with which it occurs. Since the relative pronoun (hos) is in the dative case, it should be translated "on the ground of", "by reason of", "on the condition of", "because of".
The meaning of the relative pronoun depends upon its antecedent. In the Greek language the relative pronoun agrees with its antecedent in number and gender. Here the relative pronoun is singular in number but it may be either masculine or neuter in gender. In this passage, the Greek noun thanatos (death) is the nearest singular noun, making thanatos its logical antecedent.
In this scenario then, the prepositional phrase eph hos would be equivalent to epi thanatos (because of death). In that case, the phrase should be translated "because of which" or "upon which condition."
With this meaning given to the prepositional phrase, the whole clause may be translated "because of which all sinned" and interpreted to mean that all men sinned because of the death (spiritual) that of Adam.
What this means is that Adam sinned. The result of his sin was death (separation from God). Adam was subsequently driven from the Garden and banned fro the Tree of Life.
This has resulted in a "death sentence" upon all of humanity. All of mankind is born (physically) with a spiritual separation from God.

This idea is further developed in the conversation between Jesus and Nicodemus in the third chapter of John. "Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit.” (John 3:5-6)

Here Jesus is telling Nicodemus that a spiritual birth is needed in order to have a right relationship with God, since mankind is born spiritually dead (separated from God).
Jesus is not saying that there is an inherent sinfulness to the physical birth; simply that a physical birth is not sufficient. Since God is Spirit, we must be born of the Spirit to have a relationship with Him.