The answer
From the sin of the First Man, Adam. Adam was created so that he may be in the company of God at all times. However, he rejected this fellowship, and that rejection was the beginning of what the Church calls “The Fall of Adam,” or “The Ancestral Sin,” which all of humanity inherited from its forefather Adam.
This means that the Fall of Adam is primarily the disobedience of God’s will. This an unnatural condition has been extended to all of Adam’s offspring.
In the Apostle Paul’s Epistle to the Romans, we read, “[A]s by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned” (Rom. 5:12). See also Rom. 5:18, 19.
This means that the reason why all men are sinners is Adam, the forefather of humans.
Adam, whose progeny is humanity, lost the upright life by his disobedience. As punishment, He was banished from the Paradise of Joy to the Earth, which was cursed because of his sin. On earth, He begat offspring which, by nature, was exiled and devoid of its paradisiacal inheritance (Ps. 51:5; Rom. 3:1-2).
This is in addition to the corruption of human nature, which, in turn, rendered man incapable of even keeping the moral law on his own.
It should be noted here that the sin of Adam, to us, is considered as a hereditary sin, and not actual one, for we did not commit it. We did, however, inherit from it the condemnation of death.
His Holiness Pope Tawadros II
Pope Tawadros II, My Faith: A Series of Dialogues on the Creed (Coptic Orthodox Patriarchate, 2014), 55–56.

