"That is the heresy of Pelagianism, condemned in the Third Ecumenical Council at Ephesus in 431."
That is an opinion (and council) of men, one I reject. Original sin is a teaching that defies the justice of God. Do we imprison or punish people for the crimes of their parents? No, even mortal men know that is not justice.
"For if the many died by the trespass of the one man" (Rom 5:15)
"For if, by the trespass of the one man, death reigned through that one man" (Rom 5:17)
"Consequently, just as the result of one trespass was condemnation for all men" (Rom 5:18)
"For as in Adam all die" (1 Cor 15:22)
-A8